Wrapping film and shrink film each comprising butene polymer

ABSTRACT

The wrap film and the shrink film of the present invention are formed from a resin composition comprising a specific 1-butene base polymer satisfying the following items (1) to (4) and an olefin base polymer, and they are excellent in a safety and satisfy characteristics for a wrap film or a shrink film: (1) a crystalline resin in which a melting point (Tm-D) defined as a peak top of a peak observed at a highest temperature side in a melting endothermic curve obtained by holding a sample at −10° C. for 5 minutes under nitrogen atmosphere by means of a differential scanning calorimeter (DSC) and then elevating the temperature at 10° C./minute is 0 to 100° C.; (2) a stereospecific index {(mmmm)/(mmrr+rmmr)} is 20 or less; (3) a molecular weight distribution (Mw/Mn) measured by a gel permeation chromatography (GPC) method is 4.0 or less; and (4) a weight average molecular weight (Mw) measured by the GPC method is 10,000 to 1,000,000.

BACKGROUND OF THE INVENTION

The present invention relates to a wrap film for business use or homeuse, particularly to a wrap film which does not contain chlorine and issoft to the environment and excellent in a safety and which can satisfycharacteristics required to a wrap film, such as a wrapping property, atransparency and a deformation restoring property.

Further, the present invention relates to a shrink film used forpackaging and others, particularly to a shrink film which does notcontain chlorine and is soft to the environment and excellent in asafety, a transparency and a glossiness and which can package an articlewith a good appearance without causing deformation of the wrappedarticle even when the article to be wrapped is relatively weak in a lowtemperature shrink packaging property, particularly a strength.

RELATED ART

Vegetables and fruits, meat, fishes or processed foods thereof andcooked foods such as daily dishes have so far been sold at departmentstores, supermarkets and food stores with the goods put on light-weightfoamed resin-made trays and wrapped with films. Also in homes, foods areput in a vessel and wrapped with a film in preserving by freezing andrefrigerating or in heating in an electric oven.

Characteristics such as a see-through property, a wrap-finishingappearance, a wrapping efficiency, a sticking resistance and adeformation restoring property in pushing with a finger are required tothis wrapping film. A large amount of polyvinyl chloride base resinssuch as polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC) isusually used for films which can satisfy these wrapping characteristics.

However, polyvinyl chloride base resins such as polyvinyl chloride (PVC)and polyvinylidene chloride (PVDC) contain chlorine in a molecularstructure, and therefore it has been regarded as a problem from anenvironmental point of view that they generate harmful hydrogen chloridegas by incinerating treatment carried out after used and disposed.Further, elution of plasticizers blended in a large quantity in order tosoften wrap films is also regarded as a problem from a safety point ofview.

A polyethylene base film and a polypropylene base film are tried to beused in order to solve these problems, and a part thereof is put topractical use. However, there are the problems that a polyethylene basefilm has a good low temperature characteristic but is low in a heatresistance and that a polypropylene base film has a high heat resistancebut is low in a low temperature characteristic. Further, both of thepolyethylene base film and the polypropylene base film have the problemthat they are unsatisfactory in an adhesive strength to a tray and anadhesive strength between the films themselves.

Accordingly, proposed are various methods in which a polypropylene baseresin is blended with an ethylene-propylene rubber, astyrene-ethylene-butylene-styrene block copolymer, modified polyolefin,polybutene, a hydrocarbon resin and a tackifying aid. However, theseblending compounds are not necessarily sufficiently compatible with apolypropylene base resin, and there are new problems such as roughnesson the surface, a reduction in the transparency, a reduction in thefilm-making property and bleeding of a low molecular weight compoundwhich is a tackifying aid.

In respect to the other wrap films, a wrap film formed from a resincomposition comprising 50 to 98 mass parts of a polypropylene base resin(A) and 2 to 50 mass parts of an ethylene-α-olefin copolymer (B) havinga density of 0.900 g/cm³ or less is disclosed in Japanese PatentApplication Laid-Open No. 29967/1999, and a wrap film comprising a resincomposition comprising 100 mass parts of a polypropylene base resin (A)and 1 to 15 mass parts of an oil & fat (B) is disclosed in JapanesePatent Application Laid-Open No. 29968/1999. However, a low molecularweight compound such as polybutene and an oil & fat has to besubstantially added in order to secure an adhesive property of a wrapfilm, and therefore they are not different from conventional methods.

Disclosed in Japanese Patent Application Laid-Open No. 44742/2000 is afilm comprising a soft polypropylene base resin comprising 20 to 60 mass% of (a) a polypropylene component having an isotactic index of 80 ormore and 40 to 80 mass % of (b) a copolymer component which is acopolymer component of ethylene and olefin having 4 or more carbon atomscomprising 50 to 95 mass % of ethylene and which comprises 25 to 95 mass% of a crystal component (I) containing crystalline polyethyleneinsoluble in xylene at 25° C. and 5 to 75 mass % of an amorphouscomponent (II) soluble in xylene at 25° C. However, in evaluating it asa wrap film, it is not a single layer film and is a multilayer filmcomprising a propylene-ethylene-butene-1 copolymer and an ethylene-vinylacetate copolymer as both external layers. In respect to thecharacteristics thereof as a wrap film, the polypropylene base resin isnot substantially efficiently used, and also the transparency thereofdoes not reach a satisfactory level.

Accordingly, these wrap films comprising a polyolefin base resincontaining no chlorine can solve the problem of an environmentalresistance but do not reach the level of a wrap film of a polyvinylchloride base resin, and it is the existing situation that a wrap filmcomprising a polyvinyl chloride base resin is still widely used.

On the other hand, heat shrink packaging in which a film (shrink film)having a heat shrink property is used to package an article to bepackaged and which the packaged article is then passed through a heatingfurnace to shrink the above film to thereby stick the film closely ontothe article to be packaged or tie plural articles to be packaged is usedfor outer packaging of cap noodles and integrated packaging for notesand tissue paper in many cases.

Stretched films comprising polyvinyl chloride base resins such aspolyvinyl chloride (PVC) and polyvinylidene chloride (PVDC),polyethylene base resins and polypropylene base resins are used atpresent as a shrink film used in the heat shrink packaging field.Required to the shrink film are a heat shrink property in a packagingwork, a melt-breaking resistance, a heat fusion sealing property, a hotslipping property, a transparency after packaging, a high glossiness, amechanical strength and an appearance after packaging (edges are stuckclosely well without having wrinkles). A shrink film comprising apolyvinyl chloride base resin has so far been usually used as a filmsatisfying these characteristics.

However, polyvinyl chloride base resins such as polyvinyl chloride (PVC)and polyvinylidene chloride (PVDC) contain chlorine in a molecularstructure, and therefore it has been regarded as a problem from anenvironmental point of view that they generate harmful hydrogen chloridegas by incinerating treatment after used and disposed. Further, elutionof plasticizers blended in a large quantity in order to soften wrapfilms is also regarded as a problem from a safety point of view. Also, apolyvinyl chloride base resin generates an offensive odor at a shrinkingstep in heat shrink packaging, so that an improvement thereof isrequired from the viewpoint of packaging work environment.

A polyethylene base film and a polypropylene base film are tried to beused in order to solve these problems and put to practical use. However,pointed out are the problems that the polyethylene base film has a goodlow temperature characteristic but is low in a heat resistance andinferior in a melt fusion resistance and that the polypropylene basefilm has a high heat resistance but is inferior in a low temperaturecharacteristic and an article to be packaged is deformed by a heatshrink stress as a heating temperature is elevated at a shrinking step,whereby the appearance after packaging is deteriorated and the productvalue is reduced. Further, they are inferior to a polyvinyl chloridebase resin in terms of a transparency and a glossiness, and it is theexisting situation that the use fields thereof are restricted.

Accordingly, various improvements of a shrink film using a polypropylenebase resin are proposed. Proposed in Japanese Patent ApplicationLaid-Open No. 304882/1995 is, for example, (1) a polyolefin baseresin-stretched shrink film having a specific physical property,comprising a random copolymer containing 0.01 to 5 mass % of apolybutene component, 1 to 70 mass % of a polypropylene component and 25to 98.99 mass % of a propylene-ethylene random copolymer component,wherein the above propylene-ethylene random copolymer component contains10 to 40 mole % of a monomer unit based on ethylene and 90 to 60 mole %of a monomer unit based on propylene.

Further, proposed in Japanese Patent Application Laid-Open No.176335/1997 is (2) a shrink film comprising a principal component ofcrystalline polypropylene in which a peak temperature in an elutingcurve obtained by a temperature programmed elution fractioning methodusing orthodichlorobenzene as a solvent is 90 to 110° C. and in which anelution integrating mass ratio calculated from the above eluting curveis 0 to 10 mass % at 20° C. or lower, 60 to 80 mass % at 20 to 100° C.and 10 to 40 mass % at 100 to 130° C. Used for this crystallinepolypropylene is, to be specific, a block copolymer comprising (a) 1 to70 mass % of a propylene base random copolymer comprising more than 90mole % of a polypropylene component or a monomer unit based on propyleneand (b) 30 to 99 mass % of a propylene base random copolymer comprising10 to 40 mole % of a monomer unit based on ethylene.

Further, disclosed in Japanese Patent Application Laid-Open No.152531/1998 is (3) a stretched film using a propylene base randomcopolymer which is a random copolymer of propylene and ethylene, whereina content of an ethylene unit in the copolymer, a melt index, a boilingdiethyl ether-extracting amount and a melting point satisfy a specificrelation, and an isotactic triad fraction is 98 mole % or more.

All of these propylene base resins comprise a copolymer of ethylene andthe other α-olefins as a principal component and is improved in terms ofthat a stretching temperature can be reduced, that is, a heatingtemperature in shrink packaging can be lowered. However, as apparentfrom the examples described in the respective official gazettes, thetransparency and the gloss are not still satisfactory, and they do notreach the level of polyvinyl chloride resins which have so far been usedin many case from the viewpoint of a product value of the packagedarticles.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a wrap film which hascharacteristics of a wrap film, such as a wrapping property, atransparency, a deformation restoring property and a stickingresistance, which does not contain chlorine and is not likely togenerate harmful substances such as hydrogen chloride originating inchlorine in disposing and incinerating and which is soft to the globalenvironment.

Further, an object of the present invention is to provide a shrink filmcomprising an olefin base resin, which has a good heat shrink propertyrequired to a shrink film and can be shrunk at a low temperature, whichis further improved in a transparency and a glossiness endowed toconventional polypropylene resins and has characteristics comparablewith those of a polyvinyl chloride base resin, which does not containchlorine and is not likely to generate harmful substances such ashydrogen chloride in disposing and incinerating and which is soft to theglobal environment.

Intensive investigations repeated by the present inventors in order toachieve the objects described above have resulted in finding that a filmproduced from a composition comprising a specific 1-butene base polymercan achieve the above objects. Techniques for producing a 1-butene basepolymer are disclosed in Japanese Patent Publication No. 165408/1988,Japanese Patent Publication No. 60613/1989 and Japanese PatentPublication No. 81804/1989, and 1-butene base polymers produced by theseproduction processes have problems on an impact resistance and a moldingproperty thereof, so that the uses thereof have been limited to usessuch as pipes for hot water. However, it has been found that a filmproduced from a composition comprising a specific 1-butene base polymerand an olefin base polymer has excellent characteristics as a wrap filmor a shrink film. The present invention has been completed based on suchknowledge.

That is, the present invention provides the following wrap film.

-   [1] A wrap film formed from a resin composition comprising 1 to 99    mass % of a 1-butene base polymer satisfying the following items (1)    to (4):-   (1) a crystalline resin in which a melting point (Tm-D) defined as a    peak top of a peak observed at a highest temperature side in a    melting endothermic curve obtained by holding a sample at −10° C.    for 5 minutes under nitrogen atmosphere by means of a differential    scanning calorimeter (DSC) and then elevating the temperature at 10°    C./minute is 0 to 100° C.;-   (2) a stereospecific index {(mmmm)/(mmrr+rmmr)} is 20 or less;-   (3) a molecular weight distribution (Mw/Mn) measured by a gel    permeation chromatography (GPC) method is 4.0 or less; and-   (4) a weight average molecular weight (Mw) measured by the GPC    method is 10,000 to 1,000,000-   and 99 to 1 mass % of an olefin base polymer.-   [2] A wrap film formed from a resin composition comprising 1 to 99    mass % of a 1-butene base polymer satisfying the following items    (1′) to (4′):-   (1′) a crystalline resin in which a melting point (Tm-P) defined as    a peak top of a peak observed at a highest temperature side in a    melting endothermic curve obtained by melting a sample at 190° C.    for 5 minutes under nitrogen atmosphere by means of a differential    scanning calorimeter (DSC), then lowering the temperature down to    −10° C. at 5° C./minute, holding the sample at −10° C. for 5 minutes    and then elevating the temperature at 10° C./minute is not observed    or 0 to 100° C.;-   (2′) a stereospecific index {(mmmm)/(mmrr+rmmr)} is 20 or less;-   (3′) a molecular weight distribution (Mw/Mn) measured by a gel    permeation chromatography (GPC) method is 4.0 or less; and-   (4′) a weight average molecular weight (Mw) measured by the GPC    method is 10,000 to 1,000,000-   and 99 to 1 mass % of an olefin base polymer.-   [3] A wrap film formed from a resin composition comprising 1 to 99    mass % of a 1-butene base polymer satisfying the following items (5)    and (6):-   (5) a 1-butene homopolymer or a copolymer of 1-butene and ethylene    and/or α-olefin having 3 to 20 carbon atoms (excluding 1-butene),    wherein a structural unit originating in 1-butene accounts for 90    mole % or more and-   (6) a II type crystal ratio (CII) obtained by melting a sample at    190° C. for 5 minutes, rapidly cooling it with ice and water and    solidifying, leaving standing at a room temperature for one hour and    then analyzing by X ray diffraction is 50% or less and 99 to 1 mass    % of an olefin base polymer.-   [4] The wrap film as described in any of the above items [1] to [3],    wherein the 1-butene base polymer is polymerized using a metallocene    catalyst comprising a transition metal compound in which a    cross-linking structure is formed via two cross-linking groups and a    promoter.-   [5] The wrap film as described in any of the above items [1] to [4],    wherein the olefin base polymer is a propylene base polymer.-   [6] A multilayer wrap film having at least one layer comprising the    resin composition as described in any of the above items [1] to [5].-   [7] A multilayer wrap film having at least one layer comprising the    1-butene polymer as described in any of the above items [1] to [3].-   [8] A wrap film comprising the multilayer wrap film as described in    the above item [7].

Further, the present invention provides the following shrink film.

-   [1] A shrink film formed from a resin composition comprising 1 to 99    mass % of a 1-butene base polymer satisfying the following items (1)    to (4):-   (1) a crystalline resin in which a melting point (Tm-D) defined as a    peak top of a peak observed at a highest temperature side in a    melting endothermic curve obtained by holding a sample at −10° C.    for 5 minutes under nitrogen atmosphere by means of a differential    scanning calorimeter (DSC) and then elevating the temperature at 10°    C./minute is 0 to 100° C.;-   (2) a stereospecific index {(mmmm)/(mmrr+rmmr)} is 20 or less;-   (3) a molecular weight distribution (Mw/Mn) measured by a gel    permeation chromatography (GPC) method is 4.0 or less; and-   (4) a weight average molecular weight (Mw) measured by the GPC    method is 10,000 to 1,000,000-   and 99 to 1 mass % of an olefin base polymer.-   [2] A shrink film formed from a resin composition comprising 1 to 99    mass % of a 1-butene base polymer satisfying the following items    (1′) to (4′):-   (1′) a crystalline resin in which a melting point (Tm-P) defined as    a peak top of a peak observed at a highest temperature side in a    melting endothermic curve obtained by melting a sample at 190° C.    for 5 minutes under nitrogen atmosphere by means of a differential    scanning calorimeter (DSC), then lowering the temperature down to    −10° C. at 5° C./minute, holding the sample at −10° C. for 5 minutes    and then elevating the temperature at 10° C./minute is not observed    or 0 to 100° C.;-   (2′) a stereospecific index {(mmmm)/(mmrr+rmmr)} is 20 or less;-   (3′) a molecular weight distribution (Mw/Mn) measured by a gel    permeation chromatography (GPC) method is 4.0 or less; and-   (4′) a weight average molecular weight (Mw) measured by the GPC    method is 10,000 to 1,000,000-   and 99 to 1 mass % of an olefin base polymer.-   [3] A shrink film formed from a resin composition comprising 1 to 99    mass % of a 1-butene base polymer satisfying the following items (5)    and (6):-   (5) a 1-butene homopolymer or a copolymer of 1-butene and ethylene    and/or α-olefin having 3 to 20 carbon atoms (excluding 1-butene),    wherein a structural unit originating in 1-butene accounts for 90    mole % or more and-   (6) a II type crystal ratio (CII) obtained by melting a sample at    190° C. for 5 minutes, rapidly cooling it with ice and water and    solidifying, leaving standing at a room temperature for one hour and    then analyzing by X ray diffraction is 50% or less and 99 to 1 mass    % of an olefin base polymer.-   [4] The shrink film as described in any of the above items [1] to    [3], wherein the 1-butene base polymer is polymerized using a    metallocene catalyst comprising a transition metal compound in which    a cross-linking structure is formed via two cross-linking groups and    a promoter.-   [5] The shrink film as described in any of the above items [1] to    [4], wherein the olefin base polymer is a propylene base polymer.-   [6] A multilayer shrink film having at least one layer comprising    the resin composition as described in any of the above items [1] to    [5].

BEST MODE FOR CARRYING OUT THE INVENTION

The 1-butene base polymer [1] used in the wrap film or the shrink filmof the present invention, the production process [2] for the same, thewrap film [3] and the shrink film [4] shall be explained below indetails.

1-Butene Base Polymer

The 1-butene base polymer used in the present invention is a polymerhaving the following items (1) to (4), (1′) to (4′) or (5) and (6) asrequisites [hereinafter they shall be referred to as the 1-butene basepolymer (I), the 1-butene base polymer (II) and the 1-butene basepolymer (III)]:

-   (1) a crystalline resin in which a melting point (Tm-D) defined as a    peak top of a peak observed at a highest temperature side in a    melting endothermic curve obtained by holding a sample at −10° C.    for 5 minutes under nitrogen atmosphere by means of a differential    scanning calorimeter (DSC) and then elevating the temperature at 10°    C./minute is 0 to 100° C.;-   (2) a stereospecific index {(mmmm)/(mmrr+rmmr)} is 20 or less;-   (3) a molecular weight distribution (Mw/Mn) measured by a gel    permeation chromatography (GPC) method is 4.0 or less;-   (4) a weight average molecular weight (Mw) measured by the GPC    method is 10,000 to 1,000,000;-   (1′) a crystalline resin in which a melting point (Tm-P) defined as    a peak top of a peak observed at a highest temperature side in a    melting endothermic curve obtained by melting a sample at 190° C.    for 5 minutes under nitrogen atmosphere by means of the differential    scanning calorimeter (DSC), then lowering the temperature down to    −10° C. at 5° C./minute, holding the sample at −10° C. for 5 minutes    and then elevating the temperature at 10° C./minute is not observed    or 0 to 100° C.;-   (2′) a stereospecific index {(mmmm)/(mmrr+rmmr)} is 20 or less;-   (3′) a molecular weight distribution (Mw/Mn) measured by the gel    permeation chromatography (GPC) method is 4.0 or less;-   (4′) a weight average molecular weight (Mw) measured by the GPC    method is 10,000 to 1,000,000;-   (5) a 1-butene homopolymer or a copolymer of 1-butene and ethylene    and/or α-olefin having 3 to 20 carbon atoms (excluding 1-butene),    wherein a structural unit originating in 1-butene accounts for 90    mole % or more; and-   (6) a II type crystal ratio (CII) obtained by melting a sample at    190° C. for 5 minutes, rapidly cooling it with ice and water and    solidifying, leaving standing at a room temperature for one hour and    then analyzing by X ray diffraction is 50% or less.

In the present invention, “the melting point (Tm-D) is not observed bymeans of the differential scanning calorimeter (DSC)” means that acrystallizing speed in DSC measurement is very slow, so that a crystalmelting peak can not substantially be observed. In the presentinvention, the crystalline resin means a resin in which at least eitherpeak of Tm-P and Tm-D is observed.

The 1-butene base polymer (I) or (II) used in the present invention isprovided with an excellent balance between an amount of a stickycomponent, a low elastic modulus and a transparency in the resultingwrap film or shrink film by satisfying the relation of the items (1) to(4) or (1′) to (4′) described above. That is, it has the advantage thatit is low in an elastic modulus, excellent in a soft property (referredto as a flexibility), low in a sticky component, excellent in surfacecharacteristics (for example, represented by less bleeding and lesstransferring of the sticky component onto the other products) andexcellent as well in a transparency. Further, the 1-butene base polymer[III] according to the present invention has the advantage that it doesnot have a change in physical properties with the passage of time causedby crystal modification and does not cause a shrinkage in the wrap filmor the shrink film by satisfying the items (5) and (6) described above.

In the present invention, the mesopentad fraction (mmmm) and theabnormal insertion content (1,4 insertion fraction) were determinedaccording to methods proposed in ┌Polymer Journal, 16, 717 (1984)┘reported by Asakura et al, ┌Macromol. Chem. Phys., C29, 201 (1989)┘reported by J. Randal et al and ┌Macromol. Chem. Phys., 198, 1257(1987)┘ reported by V Busico et al. That is, the signals of a methylenegroup and a methine group were measured by means of a ¹³C nuclearmagnetic resonance spectrum to determine a mesopentad fraction (mmmm)and an abnormal insertion content in a poly(1-butene) molecule. The ¹³Cnuclear magnetic resonance spectrum was measured on the followingconditions by means of the following apparatus:

-   -   Apparatus: JNM-EX400 type ¹³C-NMR apparatus manufactured by        Nippon Electron Co., Ltd.    -   Method: proton complete decoupling method    -   Concentration: 230 mg/ml    -   Solvent: a 90:10 (volume ratio) mixed solvent of        1,2,4-trichlorobenzene and heavy benzene    -   Temperature: 130° C.    -   Pulse duration: 45°    -   Pulse repeating time: 4 seconds    -   Integration: 10000 times

In the present invention, the stereospecific index {(mmmm)/(mmrr+rmmr)}was calculated from values obtained by measuring (mmmm), (mmrr) and(rmmr) by the method described above. Further, the racemitriad fraction(rr) was calculated by the method described above.

[a] 1-Butene Homopolymer

The 1-butene homopolymer (I) or (II) used in the present invention has astereospecific index {(mmmm)/(mmrr+rmmr)} of 20 or less, preferably 18or less and more preferably 15 or less. If the stereospecific indexexceeds 20, a reduction in the flexibility, the low temperature heatsealing property and the hot tacking property is brought about.

The 1-butene homopolymer (I) or (II) used in the present invention has,in addition to the requisite described above, a molecular weightdistribution (Mw/Mn) of 4.0 or less, preferably 3.5 or less andparticularly preferably 3.0 or less which is measured by the GPC method.If the molecular weight distribution (Mw/Mn) exceeds 4.0, stickiness iscaused in a certain case.

The 1-butene polymer [I] or [II] used in the present invention has, inaddition to the requisites described above, a weight average molecularweight (Mw) of 10,000 to 1,000,000, preferably 100,000 to 1,000,000 andmore preferably 100,000 to 600,000 which is measured by the GPC method.If Mw is less than 10,000, stickiness is caused in a certain case. Onthe other hand, if it exceeds 1,000,000, the fluidity is reduced, sothat the molding property is inferior in a certain case.

Mw/Mn described above is a value calculated from the weight averagemolecular weight (Mw) and the number average molecular weight (Mn) interms of polystyrene, which is measured on the following conditionsaccording to the GPC method by means of the following apparatus.

GPC Measuring Apparatus

-   -   Column: TOSO GMHHR-H(S) HT    -   Detector: RI detector for liquid chromatogram WATERS 150C        Measuring Conditions    -   Solvent: 1,2-trichlorobenzene    -   Measuring temperature: 145° C.    -   Flow velocity: 1.0 ml/minute    -   Sample concentration: 2.2 mg/ml    -   Injection amount: 160 microliter    -   Calibration curve: Universal Calibration    -   Analytical program: HT-GPC (Ver. 1.0)

When Tm-P described above is not observed, the 1-butene polymer (I) usedin the present invention has to be a crystalline resin having a meltingpoint (Tm-D) of 0 to 100° C., preferably 0 to 80° C. from the viewpointof the soft property, which is measured by means of a differentialscanning calorimeter (DSC). Tm-D is determined by DSC measurement. Thatis, a peak top of a peak observed at a highest temperature side in amelting endothermic curve obtained by holding 10 mg of a sample at −10°C. for 5 minutes under nitrogen atmosphere by means of the differentialscanning calorimeter (DSC) and then elevating the temperature at 10°C./minute is the melting point: Tm-D.

In the 1-butene homopolymer (I) used in the present invention having thestructures of (1) to (4) described above, if a melting endothermicamount ΔH-D obtained by DSC measurement in addition to the requisitesdescribed above is 50 J/g or less, it is excellent in a flexibility andtherefore preferred. ΔH-D is an index showing whether or not the polymeris soft, and if this value grows larger, it means that the elasticmodulus is high and the soft property is reduced. ΔH-D is determined bya method described later.

The 1-butene homopolymer (II) used in the present invention has to be acrystalline resin in which a melting point (Tm-P) is not observed bymeans of the differential scanning calorimeter (DSC) or is 0 to 100° C.from the viewpoint of the soft property, and if the melting point isobserved, it is preferably 0 to 80° C. Tm-P is determined by DSCmeasurement. That is, a peak top of a peak observed at a highesttemperature side in a melting endothermic curve obtained by melting 10mg of a sample at 190° C. for 5 minutes under nitrogen atmosphere bymeans of the differential scanning calorimeter (DSC), then lowering thetemperature down to −10° C. at 5° C./minute, holding the sample at −10°C. for 5 minutes and then elevating the temperature at 10° C./minute isthe melting point: Tm-P.

In the 1-butene homopolymer (II) used in the present invention havingthe structures of (1′) to (4′) described above, if a melting endothermicamount ΔH-D obtained by DSC measurement in addition to the requisitesdescribed above is 50 J/g or less, it is excellent in a flexibility andtherefore preferred, and if the amount is 10 J/g or less, it is morepreferred. ΔH-D is an index showing whether or not the polymer is soft,and if this value grows larger, it means that the elastic modulus ishigh and the soft property is reduced. ΔH-D is determined by thefollowing method. That is, a melting endothermic amount obtained bymelting 10 mg of a sample at 190° C. for 5 minutes under nitrogenatmosphere by means of the differential scanning calorimeter (DSC), thenlowering the temperature down to −10° C. at 5° C./minute, holding thesample at −10° C. for 5 minutes and then elevating the temperature at10° C./minute is ΔH-P.

The 1-butene homopolymer (I) or (II) used in the present invention has amesopentad fraction (mmmm) of preferably 20 to 90%, more preferably 30to 85% and most preferably 30 to 80%. If the mesopentad fraction is lessthan 20%, stickiness on the surface of the molded article and areduction in the transparency are likely to be brought about. On theother and, if it exceeds 90%, a reduction in the flexibility, the lowtemperature heat sealing property and the hot tacking property isbrought about in a certain case.

The 1-butene homopolymer (I) or (II) used in the present inventionsatisfies preferably the relation of (mmmm)≦90−2×(rr), more preferablythe relation of (mmmm)≦87−2×(rr). If this relation is not satisfied,stickiness on the surface of the molded article and a reduction in thetransparency are likely to be brought about.

Further, the 1-butene homopolymer (I) or (II) used in the presentinvention has preferably a 1,4 insertion fraction of 5% or less. If itexceeds 5%, a composition distribution of the polymer is expanded, andtherefore an adverse effect is likely to be exerted on the physicalproperties.

In the 1-butene base homopolymer (III) used in the present invention, aII type crystal ratio (CII) obtained by melting it at 190° C. for 5minutes, rapidly cooling with ice and water and solidifying, leavingstanding at a room temperature for one hour and then analyzing by X raydiffraction has to be 50% or less, preferably 20% or less and morepreferably 0%.

In the present invention, the II type crystal ratio (CII) was determinedaccording to a method proposed in ┌Polymer, 7, 23 (1966)┘ proposed by A.Turner Jones et al. That is, a peak in a I type crystal state and a peakin a II type crystal state were measured by X ray diffraction analysisto determine a II type crystal ratio (CII) in the crystal of the1-butene base homopolymer. X ray diffraction analysis (WAXD) was carriedout on the following conditions by means of anticathode type RotorflexRU-200 manufactured by Rigaku Denki Co., Ltd.

-   -   Sample state: molten at 190° C. for 5 minutes, rapidly cooled        with ice and water and solidified and then left standing at a        room temperature for one hour    -   Output: 30 kV, 200 mA    -   Detector: PSPC (position sensitive proportional counter)    -   Integrating time: 200 seconds

The 1-butene homopolymer (III) used in the present invention has aweight average molecular weight (Mw) of preferably 10,000 to 1,000,000which is measured by the GPC method, as the other requisite (7) inaddition to the requisites described above. It is more preferably100,000 to 1,000,000 and further preferably 100,000 to 600,000. If Mw isless than 10,000, stickiness is caused in a certain case. On the otherhand, if it exceeds 1,000,000, the fluidity is reduced, so that themolding property is inferior in a certain case. Mw/Mn and Mw describedabove are measured by the same measuring methods as described above.

The 1-butene homopolymer (I), (II) or (III) used in the presentinvention has a tensile elastic modulus of preferably 500 MPa or less,more preferably 300 MPa or less which is measured by a tensile testaccording to JIS K-7113. If it exceeds 500 MPa, the satisfactory softproperty is not obtained in a certain case.

[a′] 1-Butene Base Copolymer

The 1-butene base copolymer used in the present invention is a copolymerof 1-butene and ethylene and/or α-olefin having 3 to 20 carbon atoms(excluding 1-butene) having the above items (1) to (4), (1′) to (4′) or(5) and (6) as the requisites [hereinafter they shall be referred to asthe 1-butene base copolymer (I), the 1-butene base copolymer (II) andthe 1-butene base copolymer (III)], and it is preferably a copolymer of1-butene and α-olefin having 3 to 20 carbon atoms.

The 1-butene base copolymer (I) or (II) used in the present invention ispreferably a random copolymer. A structural unit obtained from 1-buteneaccounts for preferably 90 mole % or more, more preferably 95 mole % ormore. If the structural unit originating in 1-butene accounts for lessthan 90 mole %, stickiness on the surface of the molded article and areduction in the transparency are likely to be brought about.

The stereospecific index {(mmmm)/(mmrr+rmmr)} obtained from a (mmmm)fraction and a (mmrr+rmmr) fraction of a 1-butene chain part has to be20 or less, preferably 18 or less and more preferably 15 or less. If thestereospecific index exceeds 20, a reduction in the flexibility, the lowtemperature heat sealing property and the hot tacking property isbrought about.

The 1-butene base copolymer (I) or (II) used in the present inventionhas a molecular weight distribution (Mw/Mn) of 4.0 or less, preferably3.5 or less and particularly preferably 3.0 or less which is measured bythe gel permeation chromatography (GPC) method. If the molecular weightdistribution (Mw/Mn) exceeds 4.0, stickiness is caused in a certaincase.

The 1-butene base copolymer (I) or (II) used in the present inventionhas a weight average molecular weight Mw of 10,000 to 1,000,000,preferably 100,000 to 1,000,000 and more preferably 100,000 to 600,000which is measured by the gel permeation chromatography (GPC) method. Ifthe weight average molecular weight is less than 10,000, stickiness iscaused, and if it exceeds 1,000,000, the fluidity is reduced, so thatthe molding property is inferior in a certain case. Mw/Mn and Mwdescribed above are measured by the same measuring methods as describedabove.

In the 1-butene base copolymer (II) used in the present invention, amelting point (Tm-P) does not have to be observed by means of thedifferential scanning calorimeter (DSC) or has to be 0 to 100° C. fromthe viewpoint of the soft property, and when the melting point isobserved, it is preferably 0 to 80° C. When the melting point is notobserved, the 1-butene base copolymer (II) has to have a melting point(Tm-D) of 0 to 100° C., preferably 0 to 80° C. Tm-P and Tm-D aredetermined by the DSC measurement described above.

When the 1-butene base copolymer (I) or (II) described above was anethylene-butene copolymer, the butene content and the stereospecificindex were measured in the following manners.

The ¹³C nuclear magnetic resonance spectrum was measured on thefollowing conditions by means of a JNM-EX400 type ¹³C-NMR apparatusmanufactured by Nippon Electron Co., Ltd. to calculate the butenecontent by the following method:

-   -   Sample concentration: 220 mg/NMR solution 3 ml    -   NMR solution: 1,2,4-trichlorobenzene/benzene-d6 (90/10 vol %)    -   Measuring temperature: 130° C.    -   Pulse duration: 45°    -   Pulse repeating time: 10 seconds    -   Integration frequency: 4000 times

A signal of Sαα carbon in the ¹³C nuclear magnetic resonance spectrumwas measured on the conditions described above according to a methodproposed in ┌Macromolecules, (1982), 15, 353 to 336┘ by E. T. Hsieh andJ. C. Bandall to determine EB and BB dyad chains fractions in thepolymer chain. The butene content was determined from the respectivedyad chain fractions (mole %) thus obtained according to the followingequation:butene content(mol %)=[BB]+[EB]/2([BB] represents a butene chain fraction, and [EB] represents aethylene-butene chain fraction).

The stereospecific index was measured by the method described above.Particularly in the ethylene-butene copolymer, a peak of side chainmethylene carbon originating in a BEE chain was overlapped on a peak ofrmmr+mmrr, and therefore a peak intensity of rmmr+mmrr was corrected bydeducting a component value of a peak in Tαδ carbon of 37.5 to 37.2 froman overlapped intensity of the peak of rmmr+mmrr and the peak of sidechain methylene carbon originating in the BEE chain.

When the 1-butene base copolymer (I) or (II) described above was apropylene-butene copolymer, the butene content was measured in thefollowing manners.

The ¹³C nuclear magnetic resonance spectrum was measured on thefollowing conditions by means of the JNM-EX400 type ¹³C-NMR apparatusmanufactured by Nippon Electron Co., Ltd. to calculate the butenecontent by the following method:

-   -   Sample concentration: 220 mg/NMR solution 3 ml    -   NMR solution: 1,2,4-trichlorobenzene/benzene-d6 (90/10 vol %)    -   Measuring temperature: 130° C.    -   Pulse duration: 45°    -   Pulse repeating time: 10 seconds    -   Integration frequency: 4000 times

A signal of Sαα carbon in the ¹³C nuclear magnetic resonance spectrumwas measured on the conditions described above according to a methodproposed in ┌Macromolecules, 1978, 11, 592┘ by J. C. Bandall et al todetermine PB and BB dyad chains. The butene content was determined fromthe respective dyad chain fractions (mole %) thus obtained according tothe following equation:butene content(mol %)=[BB]+[PB]/2([BB] represents a butene chain fraction, and [PB] represents apropylene-butene chain fraction).

When the 1-butene base copolymer (I) or (II) described above was anoctene-butene copolymer, the butene content was measured in thefollowing manner.

The ¹³C nuclear magnetic resonance spectrum was measured on thefollowing conditions by means of the JNM-EX400 type ¹³C-NMR apparatusmanufactured by Nippon Electron Co., Ltd. to calculate the butenecontent by the following method:

-   -   Sample concentration: 220 mg/NMR solution 3 ml    -   NMR solution: 1,2,4-trichlorobenzene/benzene-d6 (90/10 vol %)    -   Measuring temperature: 130° C.    -   Pulse duration: 45°    -   Pulse repeating time: 10 seconds    -   Integration frequency: 4000 times

A signal of Sαα carbon in the ¹³C nuclear magnetic resonance spectrumwas measured on the conditions described above to determine OB and BBdyad chain fractions from the BB chain observed in 40.8 to 40.0 ppm andan intensity of a peak originating in the OB chain observed in 41.3 to40.8 ppm. The butene content was determined from the respective dyadchain fractions (mole %) thus obtained according to the followingequation:butene content(mol %)=[BB]+[OB]/2([BB] represents a butene chain fraction, and [OB] represents anoctene-butene chain fraction).

In the 1-butene base copolymer (III) used in the present invention, astructural unit originating in 1-butene has to account for 90 mole % ormore, preferably 95 mole % or more [the 1-butene base polymer (III) ispreferably a homopolymer].

In the 1-butene base copolymer (III) used in the present invention, a IItype crystal ratio (CII) obtained by melting it at 190° C. for 5minutes, rapidly cooling with ice and water and solidifying, leavingstanding at a room temperature for one hour and then analyzing by X raydiffraction has to be 50% or less, preferably 20% or less and morepreferably 0%. The II type crystal ratio (CII) is measured by the samemethod as described above.

The 1-butene base copolymer (III) used in the present invention has aweight average molecular weight (Mw) of preferably 10,000 to 1,000,000which is measured by the GPC method, as a requisite (7) in addition tothe requisites described above. This weight average molecular weight ismore preferably 100,000 to 1,000,000 and further preferably 100,000 to600,000. If Mw is less than 10,000, stickiness is caused in a certaincase. On the other hand, if it exceeds 1,000,000, the fluidity isreduced, so that the molding property is inferior in a certain case.Mw/Mn and Mw described above are measured by the same methods asdescribed above.

In respect to the 1-butene base copolymer used in the present invention,the α-olefin having 3 to 20 carbon atoms includes propylene, 1-pentene,4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene,1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene, and at leastone of them can be used in the present invention.

Further, the 1-butene base copolymer used in the present invention has atensile elastic modulus of preferably 500 MPa or less, more preferably300 MPa or less which is measured by the tensile test according to JISK-7113. If it exceeds 500 MPa, the satisfactory soft property is notobtained in a certain case.

[2] Production Processes for 1-butene Homopolymer (a) and 1-butene BaseCopolymer (a′)

Production processes for the 1-butene homopolymer (a) and the 1-butenebase copolymer (a′) used in the present invention include a process inwhich a catalyst system called a metallocene catalyst is used tohomopolymerize 1-butene and a process in which 1-butene is copolymerizedwith ethylene and/or α-olefin having 3 to 20 carbon atoms (excluding1-butene) in the presence of the above catalyst. The metallocenecatalyst includes transition metal compounds having one or two of acyclopentadienyl group, a substituted cyclopentadienyl group, an indenylgroup and a substituted indenyl group as ligands and catalysts obtainedby combining transition metal compounds in which the above ligands aregeometrically controlled with promoters, which are described in JapanesePatent Application Laid-Open No. 19309/1983, Japanese Patent ApplicationLaid-Open No. 130314/1986, Japanese Patent Application Laid-Open No.163088/1991, Japanese Patent Application Laid-Open No. 300887/1992,Japanese Patent Application Laid-Open No. 211694/1992 and JapanesePatent Application Laid-Open (through PCT) No. 502036/1989.

In the present invention, among the metallocene catalysts, preferred arecatalysts comprising transition metal compounds in which ligands form across-linking structure via cross-linking groups, and among them,preferred is a process in which a metallocene catalyst obtained bycombining a transition metal compound forming a cross-linking structurevia two ligands with a promoter is used to homopolymerize 1-butene or aprocess in which 1-butene is copolymerized with ethylene and/or α-olefinhaving 3 to 20 carbon atoms (excluding 1-butene) in the presence of theabove catalyst. To show the specific example thereof, given is a processin which 1-butene is homopolymerized in the presence of a catalyst forpolymerization comprising a component selected from:

-   (A) a transition metal compound represented by Formula (I):-    [wherein M represents a metal element of the 3rd to 10th groups or    a lanthanoid series in the periodic table; E¹ and E² each are    ligands selected from a substituted cyclopentadienyl group, an    indenyl group, a substituted indenyl group, a heterocyclopentadienyl    group, a substituted heterocyclopentadienyl group, an amide group, a    phosphide group, a hydrocarbon group and a silicon-containing group    and form a cross-linking group via A¹ and A², and they may be the    same as or different from each other; X represents a σ-bonding    ligand, and when plural X's are present, plural X's may be the same    or different and may cross-link with other X, E¹, E² or Y; Y    represents a Lewis base, and when plural Ys are present, plural Ys    may be the same or different and may cross-link with other Y, E¹, E²    or X; A¹ and A² are divalent cross-linking groups combining two    ligands and represent a hydrocarbon group having 1 to 20 carbon    atoms, a halogen-containing hydrocarbon group having 1 to 20 carbon    atoms, a silicon-containing group, a germanium-containing group, a    tin-containing group, —O—, —CO—, —S—, —SO₂—, —Se—, —NR¹—, —PR¹—,    —P(O)R¹—, —BR¹— or —AlR¹—; R¹ represents a hydrogen atom, a halogen    atom, a hydrocarbon group having 1 to 20 carbon atoms or a    halogen-containing hydrocarbon group having 1 to 20 carbon atoms,    and they may be the same as or different from each other; q is an    integer of 1 to 5 and represents [(a valence of M)−2]; and r    represents an integer of 0 to 3] and-   (B) (B-1) a compound which can be reacted with the transition metal    compound of the above component (A) or a derivative thereof to form    an ionic complex and (B-2) aluminoxane,-   or a process in which 1-butene is copolymerized with ethylene and/or    α-olefin having 3 to 20 carbon atoms (excluding 1-butene) in the    presence of the above catalyst.

In Formula (I) described above, M represents a metal element of the 3rdto 10th groups or a lanthanoid series in the periodic table, and thespecific examples thereof include titanium, zirconium, hafnium, yttrium,vanadium, chromium, manganese, nickel, cobalt, palladium and lanthanoidseries metals, and among them, titanium, zirconium and hafnium aresuited in terms of the olefin polymerization activity. E¹ and E² eachrepresent ligands selected from a substituted cyclopentadienyl group, anindenyl group, a substituted indenyl group, a heterocyclopentadienylgroup, a substituted heterocyclopentadienyl group, an amide group (—N<),a phosphine group —P<), a hydrocarbon group (>CR—, >C<) and asilicon-containing group (>SiR—, >Si<) (provided that R is hydrogen, ahydrocarbon group having 1 to 20 carbon atoms or a heteroatom-containing group), and they form a cross-linking structure via A¹and A². E¹ and E² may be the same as or different from each other. TheseE¹ and E² are preferably a substituted cyclopentadienyl group, anindenyl group or a substituted indenyl group.

X represents a σ-bonding ligand, and when plural X's are present, pluralX's may be the same or different and may cross-link with other X, E¹, E²or Y. The specific examples of above X include a halogen atom, ahydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, anamide group having 1 to 20 carbon atoms, a silicon-containing grouphaving 1 to 20 carbon atoms, a phosphide group having 1 to 20 carbonatoms, a sulfide group having 1 to 20 carbon atoms and an acyl grouphaving 1 to 20 carbon atoms. On the other hand, Y represents a Lewisbase, and when plural Y's are present, plural Y's may be the same ordifferent and may cross-link with other Y, E¹, E² or X. The specificexamples of the Lewis base of above Y include amines, ethers, phosphinesand thioethers.

Next, A¹ and A² are divalent cross-linking groups combining two ligandsand represent a hydrocarbon group having 1 to 20 carbon atoms, ahalogen-containing hydrocarbon group having 1 to 20 carbon atoms, asilicon-containing group, a germanium-containing group, a tin-containinggroup, —O—, —CO—, —S—, —SO₂—, —Se—, —NR¹—, —PR¹—, —P(O)R¹—, —BR¹— or—AlR¹—, in which R¹ represents a hydrogen atom, a halogen atom, ahydrocarbon group having 1 to 20 carbon atoms or a halogen-containinghydrocarbon group having 1 to 20 carbon atoms, and they may be the sameas or different from each other. Such cross-linking group includes, forexample, a group resented by a formula:

(wherein D represents carbon, silicon or tin; R² and R³ each are ahydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, andthey may be the same as or different from each other and may be combinedwith each other to form a ring structure; and e represents an integer of1 to 4), and capable of being given as the specific examples thereof aremethylene, ethylene, ethylidene, propylidene, isopropylidene,cyclohexylidene, 1,2-cyclohexylene, vinylidene (CH₂═C═),dimethylsilylene, diphenylsilylene, methylphenylsilylene,dimethylgermylene, dimethylstanylene, tetramethyldisilylene anddiphenyldisilylene. Among them, ethylene, isopropylidene anddimethylsilylene are suited. The code q is an integer of 1 to 5 andrepresents [(a valence of M)−2], and r represents an integer of 0 to 3.

Among the transition metal compounds represented by Formula (I),preferred is a transition metal compound comprising a doublecross-liking type biscyclopentadienyl derivative represented by Formula(II) as a ligand:

In Formula (II) described above, M, A¹, A², q and r are the same asdescribed above. X¹ represents a σ-bonding ligand, and when plural X¹'sare present, plural X¹'s may be the same or different and may cross-linkwith other X¹ or Y¹. The same ones as given as the examples in theexplanation of X in Formula (I) can be given as the specific examples ofthis X¹. Y¹ represents a Lewis base, and when plural Y¹'s are present,plural Y¹'s may be the same or different and may cross-link with otherY¹ or X¹. The same ones as given as the examples in the explanation of Yin Formula (I) can be given as the specific examples of this Y¹. R⁴ toR⁹ each represent a hydrogen atom, a halogen atom, a hydrocarbon grouphaving 1 to 20 carbon atoms, a halogen-containing hydrocarbon grouphaving 1 to 20 carbon atoms, a silicon-containing group or a heteroatom-containing group, and at least one of them does not have to be ahydrogen atom. R⁴ to R⁹ may be the same as or different from each other,and the adjacent groups themselves may be combined with each other toform a ring. Among them, RG and R⁷ preferably form a ring, and R⁸ and R⁹preferably form a ring. A group containing a hetero atom such as oxygen,halogen and silicon is preferred as R⁴ and R⁵ since the polymerizationactivity grows high.

This transition metal compound comprising a double cross-liking typebiscyclopentadienyl derivative as a ligand is preferably a compoundcontaining silicon in a cross-linking group between the ligands.

Capable of being given as the specific examples of the transition metalcompound represented by Formula (I) are(1,2′-ethylene)(2,1′-ethylene)-bis(indenyl)zirconium dichloride,(1,2′-methylene)(2,1′-methylene)-bis(indenyl)zirconium dichloride,(1,2′-isopropylidene)(2,1′-isopropylidene)-bis(indenyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)-bis(3-methylindenyl)-zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)-bis(4,5-benzoindenyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)-bis(4-isopropylindenyl)-zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)-bis(5,6-dimethylindenyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)-bis(4,7-diisopropylindenyl)-zirconiumdichloride, (1,2′-ethylene)(2,1′-ethylene)-bis(4-phenylindenyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)-bis(3-methyl-4-isopropylindenyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)-bis(5,6-benzoindenyl)-zirconiumdichloride, (1,2′-ethylene)(2,1′-isopropylidene)-bis(indenyl)zirconiumdichloride, (1,2′-methylene)(2,1′-ethylene)-bis(indenyl)zirconiumdichloride, (1,2′-methylene)(2,1′-isopropylidene)-bis(indenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(indenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-methylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-n-buthylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-i-propylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-trimethylsilylmethylindenyl)zirconiumdichloride, (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-phyenylindenyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(4,5-benzoindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)-(2,1′-dimethylsilylene)bis(4-isopropylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(5,6-dimethylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(4,7-di-i-propylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(4-phenylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-methyl-4-i-propylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(5,6-benzoindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)-bis(indenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)-bis(3-methylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)-bis(3-i-propylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)-bis(3-n-buthylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)-bis(3-trimethylsilylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)-bis(3-phenylindenyl)zirconiumdichloride, (1,2′-dimethylsilylene)(2,1′-methylene)-bis(indenyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-methylene)-bis(3-methylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-methylene)-bis(3-i-propylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-methylene)-bis(3-n-buthylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-methylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-methylene)-bis(3-trimethylsilylindenyl)zirconiumdichloride,(1,2′-diphenylsilylene)(2,1′-methylene)-bis(indenyl)-zirconiumdichloride,(1,2′-diphenylsilylene)(2,1′-methylene)-bis(3-methylindenyl)zirconiumdichloride,(1,2′-diphenylsilylene)(2,1′-methylene)-bis(3-i-propylindenyl)zirconiumdichloride,(1,2′-diphenylsilylene)(2,1′-methylene)-bis(3-n-buthylindenyl)zirconiumdichloride,(1,2′-diphenylsilylene)(2,1′-methylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride,(1,2′-diphenylsilylene)(2,1′-methylene)-bis(3-trimethylsilylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)-zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-methylene)(3-methylcyclopentadienyl)-(3′-methylcyclopentadienyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-isopropylidene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)-zirconiumdichloride,(1,2′-methylene)(2,1′-methylene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconiumdichloride,(1,2′-methylene)(2,1′-isopropylidene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)-zirconiumdichloride,(1,2′-isopropylidene)(2,1′-isopropylidene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-methylene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-isopropylidene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconiumdichloride,(1,2′-methylene)(2,1′-methylene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconiumdichloride(1,2′-methylene)(2,1′-isopropylidene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconiumdichloride,(1,2′-isopropylidene)(2,1′-isopropylidene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-isopropylcyclopentadienyl)(3′-methyl-5′-isopropylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-n-buthylcyclopentadienyl)(3′-methyl-5′-n-buthylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-phenylcyclopentadienyl)(3′-methyl-5′-phenylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-1-propylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methyl-5-n-buthylcyclopentadienyl)(3′-methyl-5′-n-buthylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methyl-5-phenylcyclopentadienyl)(3′-methyl-5′-phenylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-i-propylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3-methyl-5-n-buthylcyclopentadienyl)(3′-methyl-5′-n-buthylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3-methyl-5-phenylcyclopentadienyl)(3′-methyl-5′-phenylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-methylene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-methylene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-i-propylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-methylene)(3-methyl-5-n-buthylcyclopentadienyl)(3′-methyl-5′-n-buthylcylopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-methylene)(3-methyl-5-phenylcyclopentadienyl)(3′-methyl-5′-phenylcyclopentadienyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-methylene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-i-propylcyclopentadienyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-isopropylidene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-i-propylcyclopentadienyl)zirconiumdichloride,(1,2′-methylene)(2,1′-methylene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-i-propylcyclopentadienyl)zirconiumdichloride,(1,2′-methylene)(2,1′-isopropylidene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-i-propylcyclopentadienyl)zirconiumdichloride,(1,1′-dimethylsilylene)(2,2′-dimethylsilylene)bisindenyl-zirconiumdichloride,(1,1′-diphenylsilylene)(2,2′-dimethylsilylene)bisindenylzirconiumdichloride,(1,1′-dimethylsilylene)(2,2′-dimethylsilylene)-bisindenylzirconiumdichloride,(1,1′-diisopropylsilylene)(2,2′-dimethylsilylene)-bisindenylzirconiumdichloride,(1,1′-dimethylsilylene)(2,2′-diisopropylsilylene)-bisindenylzirconiumdichloride,(1,1′-dimethylsilyleneindenyl)(2,2′-dimethylsilylene-3-trimethylsilylindenyl)zirconiumdichloride,(1,1′-diphenylsilyleneindenyl)(2,2′-diphenylsilylene-3-trimethylsilylindenyl)zirconiumdichloride,(1,1′-diphenylsilyleneindenyl)(2,2′-dimethylsilylene-3-trimethylsilylindenyl)zirconiumdichloride,(1,1′-dimethylsilyleneindenyl)(2,2′-diphenylsilylene-3-trimethylsilylindenyl)zirconiumdichloride,(1,1′-diisopropylsilyleneindenyl)(2,2′-dimethylsilylene-3-trimethylsilylindenyl)zirconiumdichloride,(1,1′-dimethylsilyleneindenyl)(2,2′-diisopropylsilylene-3-trimethylsilylindenyl)zirconiumdichloride,(1,1′-diisopropylsilyleneindenyl)(2,2′-diisopropylsilylene-3-trimethylsilylindenyl)zirconiumdichloride,(1,1′-dimethylsilyleneindenyl)(2-2′-dimethylsilylene-3-trimethylsilylmethylindenyl)zirconiumdichloride,(1,1′-diphenylsilyleneindenyl)(2,2′-diphenylsilylene-3-trimethylsilylmethylindenyl)zirconiumdichloride,(1,1′-diphenylsilyleneindenyl)(2,2′-dimethylsilylene-3-trimethylsilylmethylindenyl)zirconiumdichloride,(1,1′-dimethylsilyleneindenyl)(2,2′-diphenylsilylene-3-trimethylsilylmethylindenyl)zirconiumdichloride,(1,1′-diisopropylsilyleneindenyl)(2,2′-dimethylsilylene-3-trimethylsilylmethylindenyl)-zirconiumdichloride,(1,1′-dimethylsilyleneindenyl)-(2,2′-diisopropylsilylene-3-trimethylmethylsilylindenyl)zirconiumdichloride,(1,1′-diisopropylsilyleneindenyl)(2,2′-diisopropylsilylene-3-trimethymethylsilylindenyl)zirconiumdichloride, and compounds obtained by substituting zirconium in thesecompounds with titanium or hafnium. It is a matter of course that theyshall not be restricted to these compounds. Further, they may beanalogous compounds of the other groups or metal elements of alanthanoid series. In the compounds described above, (1,1′-)(2,2′-) maybe (1,2′-)(2,1′-), and (1,2′-),(2,1′-) may be (1,1′-) (2,2′-).

Next, any compounds can be used as the (B-1) component in the component(B) as long as they can be reacted with the transition metal compound ofthe component (A) described above to form an ionic complex, andcompounds represented by the following Formulas (III) and (IV) cansuitably be used:([L¹-R¹⁰]^(k+))_(a)([Z]⁻)_(b)  (III)([L²]^(k+))_(a)([Z]⁻)_(b)  (IV)(provided that L² is M², R¹¹R¹²M³, R¹³ ₃C or R¹⁴M³)[in Formulas (III) and (IV), L¹ represents a Lewis base; [Z]⁻ representsnon-coordinate anions [Z¹]⁻ and [Z²]⁻, wherein [Z¹]⁻ represents an anionin which plural groups are combined with an element, that is, [M¹G¹G² .. . G^(f)]⁻ (in which M¹ represents a 5th to 15th group element in theperiodic table, preferably a 13th to 15th group element in the periodictable; G¹ to G^(f) each represent a hydrogen atom, a halogen atom, analkyl group having 1 to 20 carbon atoms, a dialkylamino group having 2to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an arylgroup having 6 to 20 carbon atoms, an aryloxy group having 6 to 20carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, ahalogen-substituted hydrocarbon group having 1 to 20 carbon atoms, anacyloxy group having 1 to 20 carbon atoms, an organic metalloid group ora hetero atom-containing group having 2 to 20 carbon atoms; two or moreof G¹ to G^(f) may form a ring; and f represents an integer of [(avalence of central metal M¹)+1]); [Z²]⁻ represents a Brensted acid alonein which a logarithm (pKa) of an inverse number of an acid dissociationconstant is −10 or less, a conjugate base comprising a combination of aBrensted acid and a Lewis acid or a conjugate base of an acid usuallydefined as a superstrong acid; and a Lewis base may be coordinatedtherewith; R¹⁰ represents a hydrogen atom, an alkyl group having 1 to 20carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylarylgroup or an arylalkyl group; R¹¹ and R¹² each represent acyclopentadienyl group, a substituted cyclopentadienyl group, an indenylgroup or a fluorenyl group; R¹³ represents an alkyl group having 1 to 20carbon atoms, an aryl group, an alkylaryl group or an arylalkyl group;R¹⁴ represents a macrocyclic ligand such as tertaphenylporphyrin andphthalocyanine; k is an ionic valence of [L¹-R¹⁰] and [L²] represents aninteger of 1 to 3; a represents an integer of 1 or more; b is k×a; M²contains a 1st to 3rd, 11th to 13th and 17th group element in theperiodic table; and M³ represents a 7th to 12th group element in theperiodic table].

Capable of being given as the specific examples of L¹ are ammonia,amines such as methylamine, aniline, dimethylamine, diethylamine,N-methylaniline, diphenylamine, N,N-dimethylaniline, trimethylamine,triethylamine, tri-n-butylamine, methyldiphenylamine, pyridine,p-bromo-N,N-dimethylaniline and p-nitro-N,N-dimethylaniline, phosphinessuch as triethylphosphine, triphenylphosphine and diphenylphosphine,thioethers such as tetrahydrothiophene, esters such as ethyl benzoateand nitriles such as acetonitrile and benzonitrile.

Capable of being given as the specific examples of R¹⁰ are hydrogen,methyl, ethyl, benzyl and trityl, and capable of being given as thespecific examples of R¹¹ and R¹² are cyclopentadienyl,methylcyclopentadienyl, ethylcyclopentadienyl andpentamethylcyclopentadienyl. Phenyl, p-tolyl and p-methoxyphenyl can begiven as the specific examples of R¹³, and tetraphenylporphyrin,phthalocyanine, allyl and methallyl can be given as the specificexamples of R¹⁴. Further, Li, Na, K, Ag, Cu, Br, I and I₃ can be givenas the specific examples of M². Mn, Fe, Co, Ni and Zn can be given asthe specific examples of M³.

In [Z¹]⁻, that is, [M¹G¹G² . . . G^(f)], the specific examples of M¹include B, Al, Si, P, As and Sb, preferably B and Al. Further, thespecific examples of G¹, G² to G^(f) include a dialkylamino group suchas dimethylamino and diethylamino, an alkoxy group or an aryloxy groupsuch as methoxy, ethoxy, n-butoxy and phenoxy, a hydrocarbon group suchas methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-octyl,n-eicosyl, phenyl, p-tolyl, benzyl, 4-t-butylphenyl and3,5-dimethylphenyl, a halogen atom such as fluorine, chlorine, bromineand iodine, a hetero atom-containing group such as p-fluorophenyl,3,5-difluorolphenyl, pentachlorophenyl, 3,4,5-trifluorolphenyl,pentafluorophenyl, 3,5-bis(trifluorolmethyl)phenyl andbis(trimethylsilyl)methyl and an organic metalloid group such aspentamethylantimony, trimethylsilyl, trimethylgermyl, dimethylarsine,dicyclohexylantimony and diphenylboron.

Capable of being given as the specific examples of the non-coordinateanion, that is, the conjugate base [Z²]⁻ of a Brensted acid alone inwhich pKa is −10 or less or a combination of a Brensted acid and a Lewisacid are a trifluoromethanesulfonic acid anion (CF₃SO₃)⁻, abis(trifluoromethanesulfonyl)methyl anion, abis(trifluoromethanesulfonyl)benzyl anion,bis(trifluoromethanesulfonyl)amide, a perchloric acid anion (ClO₄)⁻, atlifluoroacetic acid anion (CF₃CO₂)⁻, a hexafluoroantimony anion(SbF₆)⁻, a fluorosulfonic acid anion (FSO₃)⁻, a chlorosulfonic acidanion (ClSO₃)⁻, a fluorosulfonic acid anion/antimony pentafluoride(FSO₃/SbF₅)⁻, a fluorosulfonic acid anion/arsenic pentafluoride(FSO₃/AsF₅)⁻ and trifluoromethanesulfonic acid anion/antimonypentafluoride (CF₃SO₃/SbF₅)⁻.

Capable of being given as the specific examples of the ionic compoundwhich can be reacted with the transition metal compound of the abovecomponent (A) to form an ionic complex, that is, the (B-1) componentcompound are triethylammonium tetraphenylborate, tri-n-buthylammoniumtetraphenylborate, trimethylammonium tetraphenylborate,tetraethylammonium tetraphenylborate, methyl(tri-n-butyl)ammoniumtetraphenylborate, benzyl(tri-n-butyl)ammonium tetraphenylborate,dimethyldiphenylammonium tetraphenylborate, triphenyl(methyl)ammoniumtetraphenylborate, trimethylanilinium tetraphenylborate,methylpyridinium tetraphenylborate, benzylpyridinium tetraphenylborate,methyl(2-cyanopyridinium) tetraphenylborate, triethylammoniumtetrakis(pentafluorophenyl)borate, tri-n-butylammoniumtetrakis(pentafluorophenyl)borate, triphenylammoniumtetrakis(pentafluorophenyl)borate, tetra-n-buthylammoniumtetrakis(pentafluorophenyl)borate, tetraethylammoniumtetrakis(pentafluorophenyl)borate, benzyl(tri-n-butyl)ammoniumtetrakis(pentafluorophenyl)borate, methyldiphenylammoniumtetrakis(pentafluorophenyl)borate, triphenyl(methyl)ammoniumtetrakis(pentafluorophenyl)borate, methylaniliniumtetrakis(pentafluorophenyl)borate, dimethylaniliniumtetrakis(pentafluorophenyl)borate, trimethylaniliniumtetrakis(pentafluorophenyl)borate, methylpyridiniumtetrakis(pentafluorophenyl)borate, benzylpyridiniumtetrakis(pentafluorophenyl)borate, methyl(2-cyanopyridinium)tetrakis(pentafluorophenyl)borate, benzyl(2-cyanopyridinium)tetrakis(pentafluorophenyl)borate, methyl(4-cyanopyridinium)tetrakis(pentafluorophenyl)borate, triphenylphosphoniumtetrakis(pentafluorophenyl)borate, dimethylaniliniumtetrakis[bis(3,5-ditrifluoromethyl)phenyl]borate, ferroceniumtetraphenylborate, silver tetraphenylborate, trityl tetraphenylborate,tetraphenylporphyrinmanganese tetraphenylborate, ferroceniumtetrakis(pentafluorophenyl)borate,(1,1′-dimethylferrocenium)tetrakis(pentafluorophenyl)borate,decamethylferrocenium tetrakis(pentafluorophenyl)borate, silvertetrakis(pentafluorophenyl)borate, trityltetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, sodiumtetrakis(pentafluorophenyl)borate, tetraphenylporphyrinmanganesetetrakis(pentafluorophenyl)borate, silver tetrafluoroborate, silverhexafluorophosphate, silver hexafluoroarcenate, silver perchlorate,silver trifluoroacetate and silver trifluoromethanesulfonate.

The compounds (B-1) may be used alone or in combination of two or morekinds thereof.

On the other hand, capable of being given as aluminoxane of the (B-2)component are straight chain aluminoxane represented by Formula (V):

(wherein R¹⁵ represents a hydrocarbon group such as an alkyl grouphaving 1 to 20, preferably 1 to 12 carbon atoms, an alkenyl group, anaryl group and an arylalkyl group or a hydrogen atom; w represents anaverage polymerization degree and is an integer of usually 2 to 50,preferably 2 to 40; respective R¹⁵ may be the same of different) andcyclic aluminoxane represented by Formula (VI):

(wherein R¹⁵ and w are the same as those in Formula (V)).

A production process for the aluminoxane described above includes aprocess in which alkylaluminum is brought into contact with a condensingagent such as water, but the means therefor shall not specifically berestricted, and the reaction may be carried out according to a publiclyknown process. It includes, for example, (1) a process in which anorganic aluminum compound is dissolved in an organic solvent and inwhich this is brought into contact with water, (2) a process in which anorganic aluminum compound is added at the beginning of polymerizationand in which water is then added thereto, (3) a process in which crystalwater contained in metal salts or water adsorbed on inorganic substancesand organic substances is reacted with an organic aluminum compound and(4) a process in which tetraalkyldialuminoxane is reacted withtrialkylaluminum and in which water is further reacted therewith.Aluminoxane which is insoluble in toluene may be used.

These aluminoxanes may be used alone or in combination of two or morekinds thereof.

A use proportion of the catalyst component (A) to the catalyst component(B) falls in arrange of preferably 10:1 to 1:100, more preferably 2:1 to1:10 in terms of a mole ratio when the compound (B-1) is used as thecatalyst component (B). If the proportion deviates from the rangedescribed above, the catalyst cost per a unit mass polymer grows highand is not practical. Also, when the compound (B-2) is used, the useproportion falls in arrange of preferably 1:1 to 1:1000000, morepreferably 1:10 to 1:10000 in terms of a mole ratio. If the proportiondeviates from this range, the catalyst cost per a unit mass polymergrows high and is not practical. The compounds (B-1) and (B-2) can beused alone or in combination of two or more kinds thereof for thecatalyst component (B).

In the catalyst for polymerization in the production process for the1-butene base polymer used in the present invention, an organic aluminumcompound can be used as a component (C) in addition to the component (A)and the component (B).

In this case, used as the organic aluminum compound of the component (C)is a compound represented by Formula (VII):R¹⁶ _(v)AlJ_(3-v)  (VII)(wherein R¹⁶ represents an alkyl group having 1 to 10; J represents ahydrogen atom, an alkoxy group having 1 to 20 carbon atoms, an arylgroup having 6 to 20 carbon atoms or a halogen atom; and v is an integerof 1 to 3).

The specific examples of the compound represented by Formula (VII)described above include trimethylaluminum, triethylaluminum,triisopropylaluminum, triisobutylaluminum, dimethylaluminum chloride,diethylaluminum chloride, methylaluminum dichloride, ethylalminumdichloride, dimethylaluminum fluoride, diisobutylaluminum hydride,diethylaluminum hydride and diethylaluminum sesquichloride.

These organic aluminum compounds may be used alone or in combination oftwo or more kinds thereof.

In the production process for the 1-butene base polymer used in thepresent invention, preliminary contact can be carried out by using thecomponent (A), the component (B) and the component (C). The preliminarycontact can be carried out by bringing the component (A) into contactwith, for example, the component (B), but the method thereof shall notspecifically be restricted, and publicly known methods can be used. Thispreliminary contact is effective for reducing the catalyst cost such asa rise in the catalyst activity and a reduction in a use proportion ofthe component (B) which is a promoter. Further, a molecular weight riseeffect in addition to the effect described above is obtained by bringingthe component (A) into contact with the component (B-2). The preliminarycontact temperature is usually −20 to 200° C., preferably −10 to 150° C.and more preferably 0 to 80° C. In the preliminary contact, aliphatichydrocarbons and aromatic hydrocarbons can be used as an inerthydrocarbon solvent. Among them, aliphatic hydrocarbons are particularlypreferred.

A use proportion of the catalyst component (A) to the catalyst component(C) falls in arrange of preferably 1:1 to 1:10000, more preferably 1:5to 1:2000 and further preferably 1:10 to 1:1000 in terms of a moleratio. The polymerization activity per the transition metal can beelevated by using the above catalyst component (C), but if it is toomuch, the organic aluminum compound is in vain and remains in thepolymer in a large amount, which is not preferred.

In the present invention, at least one of the catalyst components can becarried on a suitable carrier and used. The kind of the above carriershall not specifically be restricted, and any of inorganic oxidecarriers, the other inorganic carriers and organic carriers. Inparticular, the inorganic oxide carriers and the other inorganiccarriers are preferred.

The inorganic oxide carriers include, to be specific, SiO₂, Al₂O₃, MgO,ZrO₂, TiO₂, Fe₂O₃, B₂O₃, CaO, ZnO, BaO, ThO₂ and mixtures thereof, forexample, silica-alumina, zeolite, ferrite and glass fiber. Among them,SiO₂ and Al₂O₃ are particularly preferred. The inorganic oxide carriersdescribed above may contain a small amount of carbonates, nitrates andsulfates.

On the other hand, a magnesium compound represented by a formula MgR¹⁷_(x)X¹ _(y) which is represented by MgCl₂ and Mg(OC₂H₅)₂ can be given asthe carrier other than those described above, in which R¹⁷ represents analkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20carbon atoms or an aryl group having 6 to 20 carbon atoms; X¹ representsa halogen atom or an alkyl group having 1 to 20 carbon atoms; x is 0 to2; y is 0 to 2, and x+y is 2; respective R¹⁷ and respective X¹ may bethe same or different.

Capable of being given as the organic carrier are polymer such aspolystyrene, styrene-divinylbenzene copolymers, polyethylene,poly(1-butene), substituted polystyrene and polyallylate, starch andcarbon.

MgCl₂, MgCl(OC₂H₅), Mg(OC₂H₅)₂, SiO₂ and Al₂O₃ are preferred as thecarrier used in the present invention. The properties of the carrier arevaried according to the kind and the production process thereof, and theaverage particle diameter is usually 1 to 300 μm, preferably 10 to 200μm and more preferably 20 to 100 μm.

If the particle diameter is small, fine powders in the polymer areincreased, and if the particle diameter is large, coarse particles inthe polymer are increased, which causes a reduction in the bulk densityand clogging of a hopper.

The carrier has a specific surface area of usually 1 to 1000 m²/g,preferably 50 to 500 m²/g and a pore volume of usually 0.1 to 5 cm³/g,preferably 0.3 to 3 cm³/g.

Either the specific surface area or the pore volume deviates from therange described above, the catalyst activity is reduced in a certaincase. The specific surface area and the pore volume can be determined,for example, from a volume of nitrogen gas adsorbed according to a BETmethod.

Further, when the carrier described above is the inorganic oxidecarrier, it is preferably used after incinerated at usually 150 to 1000°C., preferably 200 to 800° C.

When at least one of the catalyst components is carried on the carrierdescribed above, at least one of the component (A) and the component(B), preferably both of the component (A) and the component (B) arepreferably carried thereon.

A method for carrying at least one of the component (A) and thecomponent (B) on the above carrier shall not specifically be restricted,and capable of being used are, for example, (1) a method in which atleast one of the component (A) and the component (B) is mixed with thecarrier, (2) a method in which the carrier is treated with an organicaluminum compound or a halogen-containing silicon compound and in whichat least one of the component (A) and the component (B) is then mixedwith the carrier in an inert solvent, (3) a method in which the carrierand the component (A) and/or the component (B) are reacted with anorganic aluminum compound or a halogen-containing silicon compound, (4)a method in which the component (A) or the component (B) is carried onthe carrier and in which it is then mixed with the component (A) or thecomponent (B), (5) a method in which a catalytic reaction product of thecomponent (A) and the component (B) is mixed with the carrier and (6) amethod in which the carrier is allowed to coexist in the catalyticreaction of the component (A) and the component (B).

The organic aluminum compound of the component (C) can be added in thereactions in the methods (4), (5) and (6).

In the present invention, the catalyst may be prepared while irradiatingwith an elastic wave in bringing the components (A), (B) and (C) intocontact. The elastic wave included usually a sonic wave, particularlypreferably a supersonic wave. To be specific, it includes a supersonicwave having a frequency of 1 to 1000 kHz, preferably 10 to 500 kHz.

The catalyst thus obtained may be taken out in the form of a solid materafter distilling the solvent off and then used for polymerization or maybe used for polymerization as it is.

In the present invention, the operation of carrying at least one of thecomponent (A) and the component (B) on the carrier can be carried out inthe polymerization system to thereby form the catalyst. Capable of beingused is, for example, a method in which at least one of the component(A) and the component (B) and the carrier and, if necessary, the organicaluminum compound of the component (C) described above are added and inwhich olefin such as ethylene is added at an atmospheric pressure to 2MPa (gauge) to carry out preliminary reaction at −20 to 200° C. for oneminute to 2 hours to thereby form catalyst particles.

In the present invention, a use proportion of the component (B-1) to thecarrier is preferably 1:5 to 1:10000, more preferably 1:10 to 1:500 interms of a mass ratio, and a use proportion of the component (B-2) tothe carrier is preferably 1:0.5 to 1:10000, more preferably 1:1 to 1:50in terms of a mass ratio. When two or more kinds of the components (B)are used in a mixture, a use proportion of the respective components (B)to the carrier falls preferably in the ranges described above. Further,a use proportion of the component (A) to the carrier is preferably 1:5to 1:10000, more preferably 1:10 to 1:500 in terms of a mass ratio.

If a use proportion of the component (B) [the component (B-1) or thecomponent (B-2)] to the carrier or a use proportion of the component (A)to the carrier deviates from the range described above, the activity isreduced in a certain case. The catalyst for polymerization thus preparedhas an average particle diameter of usually 2 to 200 μm, preferably 10to 150 μm and particularly preferably 20 to 100 μm and a specificsurface area of usually 20 to 1000 m²/g, preferably 50 to 500 m²/g. Ifthe particle diameter is less than 2 μm, fine powders in the polymer areincreased in a certain case. On the other hand, if it exceeds 200 μm,coarse particles in the polymer are increased in a certain case. If thespecific surface area is less than 20 m²/g, the activity is reduced in acertain case. On the other hand, if it exceeds 1000 m²/g, the polymer isreduced in a bulk density in a certain case. Further, in the catalystused in the present invention, an amount of the transition metalcontained in the catalyst is usually 0.05 to 10 g, particularlypreferably 0.1 to 2 g per 100 g of the carrier. If an amount of thetransition metal falls outside the range described above, the activityis reduced in a certain case.

The polymer which is industrially advantageous and which has a high bulkdensity and an excellent particle diameter distribution can be obtainedby carrying the components on the carrier in the manner described above.

The 1-butene base polymer used in the present invention is produced byhomopolymerizing 1-butene or copolymerizing 1-butene with ethyleneand/or α-olefin (excluding 1-butene) using the catalyst forpolymerization described above.

In this case, the polymerization method shall not specifically berestricted, and any method of a slurry polymerization method, a gasphase polymerization method, a bulk polymerization method, a solutionpolymerization method and a suspension polymerization method may beused. The slurry polymerization method and the gas phase polymerizationmethod are particularly preferred.

In respect to the polymerizing conditions, the polymerizing temperatureis usually −100 to 250° C., preferably −50 to 200° C. and morepreferably 0 to 130° C. In respect to a use proportion of the catalystto the reaction raw materials, the raw material monomer/the component(A) described above (mole ratio) is preferably 1 to 10⁸, particularlypreferably 100 to 10⁵. Further, the polymerizing time is usually 5minutes to 10 hours, and the polymerizing pressure is preferably anatmospheric pressure to 20 MPa (gauge), more preferably an atmosphericpressure to 10 MPa (gauge).

A method for controlling a molecular weight of the polymer includesselection of the kind, a use amount and a polymerizing temperature ofthe respective catalyst components and polymerization in the presence ofhydrogen.

When a polymerization solvent is used, capable of being used are, forexample, aromatic hydrocarbons such as benzene, toluene, xylene andethylbenzene, acyclic hydrocarbons such as cyclopentane, cyclohexane andmethylcyclohexane, aliphatic hydrocarbons such as pentane, hexane,heptane and octane and halogenated hydrocarbons such as chloroform anddichloromethane. These solvents may be used alone or in combination oftwo or more kinds thereof. A monomer such as α-olefin may be used as thesolvent. The polymerization can be carried out in the absence of thesolvent depending on the polymerization method.

In the polymerization, preliminary polymerization can be carried outusing the catalyst for polymerization described above. The preliminarypolymerization can be carried out by bringing the solid catalystcomponent into contact with, for example, a small amount of olefin, butthe method therefor shall not specifically be restricted, and publiclyknown methods can be used. The olefin used for the preliminarypolymerization shall not specifically be restricted, and the same onesas given above as the examples, for example, ethylene, α-olefins having3 to 20 carbon atoms or a mixture thereof can be given. However, thesame olefin as the olefin used in the above polymerization isadvantageously used.

The preliminary polymerization temperature is usually −20 to 200° C.,preferably −10 to 130° C. and more preferably 0 to 80° C. In thepreliminary polymerization, aliphatic hydrocarbons, aromatichydrocarbons and monomers can be used as a solvent. Among them, thealiphatic hydrocarbons are particularly preferred. The preliminarypolymerization may be carried out in the absence of the solvent.

In the preliminary polymerization, the conditions are preferablycontrolled so that the preliminary polymerization product has a limitingviscosity[72] (measured in decalin of 135° C.) of 0.2 deciliter/g ormore, particularly 0.5 deciliter/g or more and an amount of thepreliminary polymerization product per millimole of the transition metalcontained in the catalyst is 1 to 10000 g, particularly 10 to 1000 g.

[3] Wrap Film

Next, the other components of the resin composition in the wrap film ofthe present invention shall be explained. The olefin base polymer whichis the other component includes polypropylene, propylene-α-olefincopolymers, propylene-ethylene-diene copolymers, high-pressure lowdensity polyethylene, high density polyethylene, ethylene-α-olefincopolymers having a density of 850 to 940 kg/m³, ethylene-vinyl acetatecopolymers, styrene base elastomers such as ethylene-styrene copolymers,styrene-butadiene diblock copolymers, styrene-butadiene-styrene triblockcopolymers, styrene-isoprene diblock copolymers andstyrene-isoprene-styrene triblock copolymers; and hydrogenated styrenebase elastomers such as hydrogenated products of styrene-butadienediblock copolymers, hydrogenated products of styrene-butadiene-styrenetriblock copolymers, hydrogenated products of styrene-isoprene diblockcopolymers and hydrogenated products of styrene-isoprene-styrenetriblock copolymers. Among them, polypropylene, propylene-α-olefincopolymers and ethylene-α-olefin copolymers having a density of 850 to940 kg/m³ are preferred, and a plurality of these olefin base polymerscan be used. The olefin base polymer is particularly preferably apropylene base polymer.

The resin composition constituting the wrap film of the presentinvention comprises 1 to 99 mass % of the 1-butene base polymer (I),(II) or (III) described above and 99 to 1 mass % of the olefin basepolymer, preferably 25 to 96 mass % of the 1-butene base polymer (I),(II) or (III) described above and 75 to 4 mass % of the olefin basepolymer, more preferably 40 to 92 mass % of the 1-butene base polymer(I), (II) or (III) described above and 60 to 8 mass % of the olefin basepolymer and most preferably 50 to 90 mass % of the 1-butene base polymer(I), (II) or (III) described above and 50 to 10 mass % of the olefinbase polymer.

In this case, if a composition ratio of the 1-butene base polymer (I),(II) or (III) described above is small, the wrap film is reduced inperformances such as a flexibility, a transparency, a deformationrestoring property and a wrapping property. On the other hand, if it islarge, the film is inferior in a film-making stability, and it becomesdifficult in a certain case to stably produce the film at a goodproductivity. Accordingly, the blending proportion thereof can suitablybe selected primarily based on a wrapping property considering, forexample, a mesopentad ratio and [η] of the 1-butene base polymer (I),(II) or (III) used and the kind, a molecular weight and a melt viscosityof the olefin base polymer.

In producing the wrap film of the present invention, publicly knownvarious additives can be blended, if desired, with the resin compositionin an amount of 0.0005 to 5%.

Various additives blended if desired include a heat resistantstabilizer, a weatherability stabilizer, an antioxidant, a neutralizingagent, a slipping agent, an antiblocking agent, a defogging agent, alubricant, a nucleating agent, a filler, a tackifier and an antistaticagent. These additives may be used alone or in combination of two ormore kinds thereof. The antioxidant includes, for example, phosphorusbase antioxidants, phenol base antioxidants and sulfur baseantioxidants.

The specific example of the phosphorus base antioxidants includetrisnonylphenyl phosphite, tris(2,4-di-t-buthylphenyl) phosphite,distearylpentaerythritol diphosphite,bis(2,4-di-t-buthylphenyl)pentaerytritol phosphite,bis(2,6-di-t-buthyl-4-methylphenyl)pentaerythritol phosphite,2,2-methylenebis(4,6-di-t-buthylphenyl)octyl phosphite,tetrakis(2,4-di-t-buthylphenyl)-4,4-biphenylene-di-phosphonite,Adekastab 1178 (manufactured by Asahi Denka Co., Ltd.), Sumilizer TNP(manufactured by Sumitomo Chemical Ind. Co., Ltd.), JP-135 (manufacturedby Johoku Chemical Co., Ltd.), Adekastab 2112 (manufactured by AsahiDenka Co., Ltd.), JPP-2000 (manufactured by Johoku Chemical Co., Ltd.),Weston 618 (manufactured by General Electric Company), Adekastab PEP-24G(manufactured by Asahi Denka Co., Ltd.), Adekastab PEP-36 (manufacturedby Asahi Denka Co., Ltd.), Adekastab HP-10 (manufactured by Asahi DenkaCo., Ltd.), Sandstab P-EPQ (manufactured by Sand Co., Ltd.) andPhosphite 168 (manufactured by Ciba Specialty Chemicals Co., Ltd.).

The specific example of the phenol base antioxidants include2,6-di-t-buthyl-4-methylphenol,n-octadecyl-3-(3′,5′-di-t-buthyl-4′-hydroxyphenyl)propionate,tetrakis[methylene-3-(3,5-di-t-buthyl-4-hydroxyphenyl)propionate]methane,tris(3,5-di-t-buthyl-4-hydroxybenzyl)isocyanurate,4,4′-butylidenebis-(3-methyl-6-t-buthylphenol), triethyleneglycol-bis[3-(3-t-buthyl-4-hydroxy-5-methylphenyl)propionate],3,9-bis{2-[3-(3-t-buthyl-4-hydroxy-5-methylphenyl)propioniloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane,Smilizer BHT (manufactured by Sumitomo Chemical Ind. Co., Ltd.),Yoshinox BHT (manufactured by Yoshitomi Seiyaku Co., Ltd.), Antage BHT(manufactured by Kawaguchi Chemical Industry Co., Ltd.), Irganox 1076(manufactured by Ciba Specialty Chemicals Co., Ltd.), Irganox 1010(manufactured by Ciba Specialty Chemicals Co., Ltd.), Adekastab AO-60(manufactured by Asahi Denka Co., Ltd.), Smilizer BP-101 (manufacturedby Sumitomo Chemical Co., Ltd.), Tominox TT (manufactured by YoshitomiSeiyaku Co., Ltd.), TTHP (manufactured by Toray Industries, Inc.),Irganox 3114 (manufactured by Ciba Specialty Chemicals Co., Ltd.),Adekastab AO-20 (manufactured by Asahi Denka Co., Ltd.), Adekastab AO-40(manufactured by Asahi Denka Co., Ltd.), Smilizer BBM-S (manufactured bySumitomo Chemical Ind. Co., Ltd.), Yoshinox BB (manufactured byYoshitomi Seiyaku Co., Ltd.), Antage W-300 (manufactured by KawaguchiChemical Industry Co., Ltd.), Irganox 245 (manufactured by CibaSpecialty Chemicals Co., Ltd.), Adekastab AO-70 (manufactured by AsahiDenka Co., Ltd.), Tominox 917 (manufactured by Yoshitomi Seiyaku Co.,Ltd.), Adekastab AO-80 (manufactured by Asahi Denka Co., Ltd.) andSmilizer GA-80 (manufactured by Sumitomo Chemical Co., Ltd.).

The specific example of the sulfur base antioxidants includedilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate,distearyl-3,3′-thiodipropionate,pentaelysritoltetrakis(3-laurylthiopropionate), Smilizer TPL(manufactured by Sumitomo Chemical Ind. Co., Ltd.), Yoshinox DLTP(manufactured by Yoshitomi Seiyaku Co., Ltd.), Antiox L (manufactured byNOF Corporation), Smilizer TPM (manufactured by Sumitomo Chemical Ind.Co., Ltd.), Yoshinox DMTP (manufactured by Yoshitomi Seiyaku Co., Ltd.),Antiox M (manufactured by NOF Corporation), Smilizer TPS (manufacturedby Sumitomo Chemical Ind. Co., Ltd.), Yoshinox DSTP (manufactured byYoshitomi Seiyaku Co., Ltd.), Antiox S (manufactured by NOFCorporation), Adekastab AO-412S (manufactured by Asahi Denka Co., Ltd.),SEENOX 412S (manufactured by Sipro Chemicals Co., Ltd.) and Smilizer TPS(manufactured by Sumitomo Chemical Ind. Co., Ltd.).

Among them, particularly preferred are Irganox 1010: material name:pentaerythrityl-tetrakis[3-(3,5-di-t-buthyl-4-hydroxyphenyl)-propionate,Irgafos 168: material name: tris(2,4-di-t-buthylphenyl)phosphite,Irganox 1076: material name:octadecyl-3-(3,5-di-t-buthyl-4-hydroxyphenyl)propionate, Irganox 1330:material name:1,3,5-trimethyl-2,4,6-tris(3,5,-di-t-buthyl-4-hydroxybenzyl)benzene,Irganox 3114: material name:tris(3,5-di-t-buthyl-4-hydroxybenzyl)isocyanurate and P-EPQ: materialname: tetrakis(2,4-di-t-buthylphenyl)-4,4′-biphenylene-di-phosphite.

When the antioxidant is used in the present invention, it is addedpreferably in an amount of 0.001 to 1 mass part per 100 mass parts ofthe sum of the 1-butene base polymer and the olefin base polymer. Thiscan prevent yellowing and therefore is preferred.

To give the specific use examples of the antioxidants described above,they are: Example 1: Irganox 1010 1,000 ppm PEP-Q 1,000 ppm Example 2:Irganox 1076 1,200 ppm PEP-Q 600 ppm Irgafos 168 800 ppm Example 3:Irganox 1010 400 to 1,000 ppm Irgafos 168 700 to 1,500 ppm

Particularly preferred as the neutralizing agent are calcium stearate,zinc stearate, magnesium stearate and hydiotalcite (DHT-4A): compositionformula: Mg_(4.5)Al₂(OH)₁₃CO₃.3.5H₂O, Li₂Al₄(OH)₁₂CO₃.3H₂O (┌MizukalacH-1┘ manufactured by Mizusawa Chemical Co., Ltd.).

Particularly preferred as the antiblocking agent are ┌Silysia┘:synthetic silica manufactured by Fuji Silysia Co., Ltd. and ┌Mizukasil┘:synthetic silica manufactured by Mizusawa Chemical Co., Ltd.

Particularly preferred as the slipping agent are erucamide, oleamide,stearamide, behenamide, ethylenebisstearamide, ethylenebisoleamide,stearylerucamide and oleylpalmitamide.

Capable of being given as the defogging agent are glycerin fatty acidester compounds such as (di)glycerin mono(di, tri)oleate, (di)glycerinmono(di, tri)stearate, (di)glycerin mono(di)palmitate and (di)glycerinmono(di)laurate, sorbitan fatty acid ester compounds such as sorbitanlaurate, sorbitan palmitate, sorbitan (tri)stearate and sorbitan(tri)oleate, ethylene oxide adducts such as polyoxyethylenealkyl(phenyl)ether, polyoxyethylene sorbitan monooleate andpolyoxyethylene glycerin monostearate and propylene glycol fatty acidester compounds such as propylene glycol monolaurate, propylene glycolmonopalmitate, propylene glycol monostearate and propylene glycolmonooleate. A plurality of these defogging agents can be used. Use ofthe defogging agent makes it possible to prevent fogging caused by steamcoming from a wrapped article and enhance the value of a displayedproduct by maintaining a see-through property.

When using the nucleating agent, an addition amount of the nucleatingagent falls in a range of usually 10 ppm or more, preferably 10 to10,000 ppm, more preferably 10 to 5,000 ppm and further preferably 10 to2,500 ppm based on the resin composition comprising the 1-butene basepolymer (I), (II) or (III).

A petroleum resin, a terpene resin, a coumarone-indene resin, a rosinbase resin or a hydrogenated derivative thereof can be added as thetackifier. Addition of these tackifiers makes it easy to control astickiness in the wrap film. The petroleum resin includes alicyclicpetroleum resins formed from cyclopentadiene or a dimer thereof andaromatic petroleum resins formed from C9 components, and the terpeneresin includes terpene resins prepared from β-pinene and terpene-phenolresins. Capable of being given as the examples of the rosin base resinare rosin resins such as gum rosin and wood rosin and esterified rosinresins which are modified with glycerin and pentaerythritol.

The hydrogenated derivative includes hydrogenated aromatic hydrocarbonresins, hydrogenated aliphatic hydrocarbon resins, hydrogenatedalicyclic hydrocarbon resins, hydrogenated aliphatic-alicyclichydrocarbon resins and hydrogenated aliphatic-aromatic hydrocarbonresins. To be specific, it includes hydrogenated terpene resins,hydrogenated polycyclopentadiene resins and hydrogenatedα-methylstyrene- vinyltoluene resins.

The resin composition forming the wrap film of the present invention canbe produced by a method in which the specific 1-butene base polymer (I),(II) or (III) described above, the olefin base polymer and variousadditives added if necessary are added in the prescribed amounts and inwhich the mixture is pelletized by a conventional method, for example,by means of a melt-blending machine such as an extrusion-molding machineand a Banbury mixer.

For example, a T die molding method, an inflation molding method and acalendar molding method can be used as a method for forming the wrapfilm of the present invention using the composition pellets thusobtained. In a method for molding the film, the resin is heated at amolding resin temperature of 190 to 270° C., extruded and cooled,whereby the film is produced. Either of air cooling and water coolingcan be used as the cooling method.

Even if the wrap film of the present invention is a non-stretched film,it has sufficiently a function as a wrap film. However, it can bebiaxially stretched, if necessary, by a publicly known method. Thisstretching makes it possible to enhance a cutting property of the wrapfilm. The wrap film of the present invention has a thickness falling ina range of usually 5 to 40 μm, preferably 10 to 20 μm, and it issuitably determined considering the uses and the use forms of the wrapfilm.

The wrap film of the present invention is based on a single layer filmcomprising the resin composition described above, but it can be amultilayer film having at least one layer comprising this resincomposition. The above multilayer film may be a multilayer film fallingin the range of the requisites of the specific 1-butene base polymer(I), (II) or (III) used in the present invention or may be a multilayerfilm comprising the resin composition in which the requisites and thecomposition ratio are the same and in which the additive prescription isdifferent.

Further, it can be a multilayer film comprising the resin compositionlayer forming the wrap film of the present invention and at least onelayer formed from a resin suitably selected from the other olefin baseresins. In this case, a proportion of the layer comprising the resincomposition containing the specific 1-butene base polymer (I), (II) or(III) falls in a range of 1 to 99%, preferably 20 to 80%. The wrap filmof the present invention may be a multilayer film which has at least onelayer comprising only the 1-butene base polymer (I), (II) or (III) andin which the other olefin base resin layer is laminated on one face orboth faces thereof A resin suitably selected from those given as theexamples in the olefin base polymer used in producing the wrap filmdescribed above can be used for the other olefin base resin in themultilayer film. Lamination of the other olefin base resin layercontrols a viscoelastic characteristic of the film, improves a moldingprocessability, an appearance, a flexibility and a tensilecharacteristic of the film to result in showing suited stretching andimproves stretching at a low temperature. The multilayer film may beconstituted from two or more layers. The wrap film has preferably a twokind-three layer structure in which the resin layer comprising the1-butene base polymer (I), (II) or (III) is an intermediate layer and inwhich both surface layers are the polyolefin base resin layers.

Further preferred as the polyolefin base resin material laminated arelow density polyethylene, very low density polyethylene (copolymer ofethylene and α-olefin), ethylene-vinyl acetate copolymers (EVA),ethylene-alkyl acrylate copolymers, ethylene-alkyl methacrylatecopolymers, ethylene-acrylic acid copolymers, ethylene-methacrylic acidcopolymers, ionomer resins and propylene base elastomer materials.

EVA and/or straight chain ethylene-α-olefin copolymers can suitably beused for the wrap film, and the proportion thereof in mixing may beoptional. Suited as this EVA is a resin having a vinyl acetate contentof 5 to 25 mass %, preferably 10 to 20 mass % and a melt flow rate (MFR)of 0.1 to 20 g/10 minutes, preferably 0.5 to 10 g/10 minutes which ismeasured at a temperature of 190° C. and a load of 21.2N according toJIS K-7210. In this case, if the vinyl acetate content is less than 5mass %, the resulting film is hard and reduced in a flexibility and anelasticity restoring property, and the surface adhesive property is lessliable to be revealed in a certain case. On the other hand, if itexceeds 25 mass %, the surface adhesive property becomes too strong, andthe film is liable to be reduced in a winding-off property and anappearance in a certain case.

Suited as the straight chain ethylene-α-olefin copolymer is a polymerhaving an α-olefin content of 1 to 40 mass %, preferably 2 to 30 mass %and a melt flow rate (MFR) of 0.1 to 20 g/10 minutes, preferably 0.5 to10 g/10 minutes which is measured at a temperature of 190° C. and a loadof 21.2N according to JIS K-7210. In this case, if the α-olefin contentis less than 1 mass %, the resulting film is hard, and a uniformextensibility is less liable to be obtained in stretch wrapping, so thatwrinkles are likely to be produced on the wrapped article, and thewrapped article is likely to be liable to collapse. On the other hand,if it exceeds 40 mass %, it is likely to be difficult to mold the film,and the film is likely to be reduced in a winding-off property.

The α-olefin is preferably 1-butene, 1-hexene, 4-methyl-1-pentene and1-octene which have 4 to 8 carbon atoms. They can be used alone or incombination of two or more kinds thereof. If both of EVA and thestraight chain ethylene-α-olefin copolymer have an MFR of less than 0.1g/10 minutes, the extrusion processability is reduced. On the otherhand, if it exceeds 20 g/10 minutes, the film-making stability isreduced, and thickness unevenness and a reduction and a dispersion inthe dynamic strength are liable to be brought about.

In both surface layer or an intermediate layer in the multilayer film ofthe present invention, publicly known various additives can be blended,if desired, in an amount of 0.0005 to 5%.

Various additives blended if desired include a heat resistantstabilizer, a weatherability stabilizer, an antioxidant, a neutralizingagent, a slipping agent, an antiblocking agent, a defogging agent, alubricant, a nucleating agent, a filler, a tackifier and an antistaticagent. The specific examples of these additives are the same asdescribed above.

The wrap film can be provided with a strong adhesive property on anexternal layer by adding 3 to 6 mass % of a liquid rubber such aspolybutene as a tackifier to L-LDPE (linear low density polyethylene) orEVA forming the other external layer and therefore it is suited. Apetroleum resin, a terpene resin, a coumarone-indene resin, a rosin baseresin or a hydrogenated derivative thereof can be added as thetackifier. Addition of these tackifiers makes it easy to control astickiness in the wrap film. The petroleum resin includes alicyclicpetroleum resins formed from cyclopentadiene or a dimer thereof andaromatic petroleum resins formed from C9 components, and the terpeneresin includes terpene resins prepared from β-pinene and terpene-phenolresins. Capable of being given as the examples of the rosin base resinare rosin resins such as gum rosin and wood rosin and esterified rosinresins which are modified with glycerin and pentaerythritol.

The hydrogenated derivative includes hydrogenated aromatic hydrocarbonresins, hydrogenated aliphatic hydrocarbon resins, hydrogenatedalicyclic hydrocarbon resins, hydrogenated aliphatic-alicyclichydrocarbon resins and hydrogenated aliphatic-aromatic hydrocarbonresins. To be specific, it includes hydrogenated terpene resins,hydrogenated polycyclopentadiene resins and hydrogenatedα-methylstyrene-vinyltoluene resins.

The multilayer wrap film of the present invention has a thickness of 8to 30 μm, preferably 10 to 20 μm. In the multilayer film, a proportionof the layer comprising the resin composition containing the 1-butenebase polymer (I), (II) or (III) described above falls in a range of 1 to99%, preferably 20 to 80%, and it is more preferably 30 to 70% in termsof various characteristics and the economical efficiency.

The multilayer wrap film of the present invention is obtained byco-extruding by a multilayer die in a layer structure of a two kind-twolayer, preferably two kind-three layer by means of plural extrudingmachines and molding by a T die molding method or an inflation moldingmethod.

In the T die molding, the composition of a non-stretching state may beused as it is or the film may be molded by molding a raw film comprisinga laminated matter and then biaxially stretching this film in bothlongitudinal and lateral directions. In the order of stretching, eitherlongitudinal or lateral stretching may be carried out first, orlongitudinal and lateral stretching may be carried out at the same time.The film is biaxially stretched in longitudinal and lateral directionsat a stretching magnification of 2 to 5 times, preferably 2.5 to 4.5times respectively. If this stretching magnification is less than 2times, a cutting property of the film is unsatisfactory. On the otherhand, if it is larger than 5 times, the stretching property is reducedto cause breakage or stretching unevenness on the film. Further, heatfixing may be carried out, if necessary, after stretching.

The inflation molding method is a molding method in which a resincomposition is molten and extruded from an ring die, and in this case,the blow-up ratio (valve ratio/die diameter) is preferably 4 or more,particularly preferably 5 to 7. A cooling method in melt-extruding maybe either of a method for cooling from an external face of a tube and amethod for cooling from both of an external face and an internal face ofa tube.

The wrap film of the present invention thus obtained is excellent in asafety, a flexibility, a wrapping property (an adhesive property), atransparency, a deformation restoring property, a sticking resistanceand a cutting property, and it does not discharge harmful substances indisposing and incinerating and is soft to the global environment.Accordingly, the wrap film of the present invention can suitably be usedas a wrap film for business use and home use in packaging resin-foamedtrays for foods and preserving by freezing and refrigerating.

[4] Shrink Film

Next, the other components of the resin composition in the shrink filmof the present invention shall be explained. The olefin base polymerwhich is the other component includes the same ones as in the case ofthe wrap film. That is, the olefin base polymer includes polypropylene,propylene-α-olefin copolymers, propylene-ethylene-diene copolymers,high-pressure low density polyethylene, high density polyethylene,ethylene-α-olefin copolymers having a density of 850 to 940 kg/m³,ethylene-vinyl acetate copolymers and hydrogenated styrene baseelastomers. Among them, polypropylene, propylene-α-olefin copolymers andethylene-α-olefin copolymers having a density of 850 to 940 kg/m³ arepreferred, and a plurality of these olefin base polymers can be used.The olefin base polymer is particularly preferably a propylene basepolymer.

The resin composition constituting the shrink film of the presentinvention comprises 1 to 99 mass % of the 1-butene base polymer (I),(II) or (III) described above and 99 to 1 mass % of the olefin basepolymer, preferably 20 to 96 mass % of the 1-butene base polymer (I),(II) or (III) described above and 80 to 4 mass % of the olefin basepolymer, more preferably 30 to 94 mass % of the 1-butene base polymer(I), (II) or (III) described above and 70 to 6 mass % of the olefin basepolymer and most preferably 40 to 92 mass % of the 1-butene base polymer(I), (II) or (III) described above and 60 to 8 mass % of the olefin basepolymer.

In this case, if a composition ratio of the 1-butene base polymer (I),(II) or (III) described above is small, deformation and breakage of thewrapped article are liable to be brought about by heat contraction ofthe film to reduce the performances of the shrink film such as a packageappearance. On the other hand, if it is large, the film is inferior in afilm-making stability and a stretching property, and it becomesdifficult in a certain case to stably produce the film at a goodproductivity. Accordingly, the blending proportion thereof can suitablybe selected primarily based on a packaging property, a film-makingproperty and a stretching property considering, for example, amesopentad fraction and [η] of the 1-butene base polymer (I), (II) or(III) used and the kind, a molecular weight and a melt viscosity of theolefin base polymer.

In producing the shrink film of the present invention, publicly knownvarious additives can be blended if desired. Various additives blendedif desired include an antioxidant, a neutralizing agent, a slippingagent, an antiblocking agent, a defogging agent, a lubricant, anucleating agent or an antistatic agent. These additives may be usedalone or in combination of two or more kinds thereof. The antioxidantincludes, for example, phosphorus base antioxidants, phenol baseantioxidants and sulfur base antioxidants.

The specific examples of the phosphorus base antioxidants, the phenolbase antioxidants and the sulfur base antioxidants include the same onesas those given as the examples in the explanations of the wrap film. Thesame ones as in the wrap film shall apply to the specific examples ofthe preferred antioxidant, a use amount of the antioxidant and thespecific use examples of the antioxidant.

The same ones as in the wrap film can be used as the neutralizing agent,the antiblocking agent, the slipping agent and the defogging agent. Whenusing the nucleating agent, an addition amount of the defogging agentfalls, as is the case with the wrap film, in a range of usually 10 ppmor more, preferably 10 to 10,000 ppm, more preferably 10 to 5,000 ppmand further preferably 10 to 2,500 ppm based on the resin compositioncomprising the 1-butene base polymer (I), (II) or (III) and the olefinbase polymer.

The resin composition constituting the shrink film of the presentinvention can be produced by a method in which the specific 1-butenebase polymer (I), (II) or (III) described above, the olefin base polymerand various additives added if necessary are added in the prescribedamounts and in which the mixture is pelletized by a conventional method,for example, by means of a melt-blending machine such as anextrusion-molding machine and a Banbury mixer.

The shrink film of the present invention can be obtained by producing araw film for stretching by a publicly known melt extrusion-moldingmethod using the compositional pellets thus obtained and then stretchingthis raw film in two longitudinal and lateral directions. Usually, a Tdie cast film-making method or an inflation film-making method is usedfor this melt extrusion-molding method to produce a raw film forstretching having a thickness falling in a range of 100 to 700 μm,preferably 200 to 500 μm. In the molding method for the raw film, thefilm is produced by heating the resin at a molding resin temperature of190 to 270° C., extruding and cooling it. Either of air cooling andwater cooling can be used as the cooling method.

Next, this raw film for stretching is stretched in two longitudinal andlateral directions, that is, biaxially by a tenter method when using theT die cast film-making method and a tubular method when using theinflation film-making method. In this biaxial stretching, the film maybe biaxially stretched in two longitudinal and lateral directions at thesame time in the case of the tenter method or may be stretched by amultistage biaxial stretching method in which the film is stretchedseparately in a longitudinal direction and a lateral direction. Thestretching magnifications in the longitudinal and lateral directionseach are 1.5 to 20 times, preferably 2 to 17 times and more preferably 3to 15 times. The conditions in stretching such as a heating conditionand a stretching speed are suitably selected considering variousphysical properties of the 1-butene base polymer (I), (II) or (III),various physical properties of the olefin base polymer, a blendingproportion of both polymers, a melting characteristic of the compositionand a thickness and a stretching magnification of the raw film forstretching. The shrink film of the present invention can be subjected aswell, if necessary, to heat treatment on suitable conditions afterbiaxially stretched.

The shrink film of the present invention is based on a single layer filmcomprising the resin composition described above, but it can be amultilayer film having at least one layer comprising this resincomposition. The above multilayer film may be a multilayer film fallingin the range of the requisites of the specific 1-butene base polymer(I), (II) or (III) used in the present invention or may be a multilayerfilm comprising the resin composition in which the requisites and thecomposition ratio are the same and in which the additive prescription isdifferent.

Further, it can be a multilayer film comprising the resin compositionlayer forming the shrink film of the present invention and at least onelayer formed from a resin suitably selected from the other olefin baseresins. In this case, a proportion of the layer comprising the resincomposition containing the specific 1-butene base polymer (I), (II) or(III) falls in a range of 1 to 99%, preferably 20 to 80%. Thecharacteristics of the present invention can efficiently be used byproviding this layer on one external layer, and therefore it ispreferred. A resin suitably selected from those given as the examples inthe olefin base polymer used in producing the shrink film of the presentinvention can be used for the other olefin base resin in the multilayerfilm.

The shrink film of the present invention thus obtained is excellent in aheat shrinkability, a heat melt-sealing property, a hot slippingproperty, a safety, a flexibility, a shrink packaging appearance, atransparency and a breakage resistance of a wrapped article, and it doesnot discharge harmful substances originating in chlorine in disposingand incinerating and is soft to the global environment. Accordingly, theshrink film of the present invention can suitably be used for packagingof individual foods such as cap noodle, multiple batch packaging ofyogurt put in a container, fruit-processed foods and dairy products,multiple batch packaging of canned beer and canned juice and heat shrinkpackaging of various articles such as notes and stationeries.

The present invention shall more specifically be explained below basedon examples, but the present invention shall by no means be restrictedby these example.

PRODUCTION EXAMPLE 1 Production of 1-butene Polymer

(1) Synthesis of Complex

Synthesis of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)-zirconiumdichloride

A lithium salt 3.0 g (6.97 millimole) of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(indene) was dissolvedin 50 ml of THF in a Shrenk bottle, and the solution was cooled to −78°C. Iodomethyltrimethylsilane 2.1 ml (14.2 millimole) was slowly dropwiseadded thereto and stirred at a room temperature for 12 hours. Thesolvent was distilled off, and 50 ml of ether was added thereto,followed by washing the solution with a saturated ammonium chloridesolution. After separating the solution, the organic layer was dried,and the solvent was distilled off to obtain 3.04 g (5.88 millimole) of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindene)(yield: 84%).

Next, 3.04 g (5.88 millimole) of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindene)obtained above and 50 ml of ether were put in a Shrenk bottle undernitrogen flow. The solution was cooled to −78° C., and 7.6 ml (11.7millimole) of n-BuLi (hexane solution 1.54M) was added thereto, followedby stirring the solution at a room temperature for 12 hours. The solventwas distilled off, and a solid matter thus obtained was washed with 40ml of hexane, whereby 3.06 g (5.07 millimole) of the lithium salt wasobtained in the form of an ether adduct (yield: 73%).

The result of measurement by ¹H-NMR (90 MHz, THF-d₈) was:

-   δ 0.04 (s, 18H, trimethylsilyl), 0.48 (s, 12H, dimethylsilylen),    1.10 (t, 6H, methyl), 2.59 (s, 4H, methylene), 3.38 (q, 4H,    methylene), 6.2-7.7 (m, 8H, Ar—H).

The lithium salt obtained above was dissolved in 50 ml of toluene undernitrogen flow. The solution was cooled to −78° C., and a toluene (20 ml)suspension of 1.2 g (5.1 millimole) of zirconium tetrachloride which wascooled in advance to −78° C. was dropwise added thereto. After dropwiseadded, the solution was stirred at a room temperature for 6 hours. Thesolvent was distilled off from the reaction liquid, and the resultingresidue was recrystallized from dichloromethane, whereby obtained was0.9 g (1.33 millimole) of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride (yield: 26%).

The result of measurement by ¹H-NMR (90 MHz, CDCL₃) was:

-   δ 0.0 (s, 18H, trimethylsilyl), 1.02, 1.12 (s, 12H,    dimethylsilylene), 2.51 (dd, 4H, methylene), 7.1-7.6 (m, 8H, Ar—H).    (2) Production of 1-butene Polymer

An autoclave of 10 liter which was dried by heating was charged with 4liter of heptane, 2.5 kg of 1-butene, 10 millimole oftriisobutylaluminum and 10 millimole of methylaluminoxane, and 0.05 MPaof hydrogen was further introduced thereinto. The temperature was raisedto 60° C. while stirring, and then added thereto was 10 micromole of(1.33 millimole) of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride of the catalyst prepared in (1) described above to carry outpolymerization for 60 minutes. After finishing the polymerizationreaction, the reaction product was dried under reduced pressure tothereby obtain 990 g of a 1-butene polymer. The following evaluationresults of the resin characteristics of the 1-butene polymer thusobtained were as follows. Mesopentad fraction (mmmm): mol % 71.6Racemitriad fraction (rr): mol % 4.6 91 − 2 × (rr) 80.8 Abnormalinsertion amount (1,4 insertion fraction): mol % 0 Stereospecific index(mmmm)/(mmrr + rmmr) 8 Weight average molecular weight (Mw) 51 × 10⁴Molecular weight distribution (Mw/Mn) 2.0 Melting point (Tm-P: DSCmeasurement): ° C. not observed Melt endothermic amount (ΔH-P): J/g notobserved Melting point (Tm-D: DSC measurement): ° C. 73 Melt endothermicamount (ΔH-D): J/g 35 CII: % 0

The resin characteristics describe above were measured in the followingmanners.

-   (1) Measurement of mesopentad fraction, racemitriad fraction and    abnormal insertion amount

Measured by the methods described in the present specification.

-   (2) Measurement of weight average molecular weight (Mw) and    molecular weight distribution (Mw/Mn)

Measured by the methods described in the present specification.

-   (3) DSC measurement (melting point: measurement of Tm-P and Tm-D)

Designated as ΔH-P was a melting endothermic amount obtained by melting10 mg of the sample at 190° C. for 5 minutes under nitrogen atmosphereby means of a differential scanning calorimeter (DSC-7 manufactured byPerkin Elmer Co., Ltd.), then lowering the temperature down to −10° C.at 5° C./minute, holding the sample at −10° C. for 5 minutes and thenelevating the temperature at 10° C./minute. A peak top of a peakobserved at a highest temperature side in the melt endothermic curvethus obtained was designated as the melting point: Tm-P.

Designated as ΔH-D was a melting endothermic amount obtained by holding10 mg of the sample at −10° C. for 5 minutes under nitrogen atmosphereby means of the differential scanning calorimeter (DSC-7 manufactured byPerkin Elmer Co., Ltd.) and then elevating the temperature at 10°C./minute. A peak top of a peak observed at a highest temperature sidein the melt endothermic curve thus obtained was designated as themelting point: Tm-D.

(4) Measurement of II Type Crystal Ratio (CII)

Measured by the methods described in the present specification.

EXAMPLES 1 TO 4

(1) Production of Pellets

A phenol base antioxidant: Irganox 1010: 500 ppm and a phosphorus baseantioxidant: Irgafos 168: 1000 ppm were added to the 1-butene polymerobtained above, and the polymer was extrusion-molded at a resintemperature of 200° C. by means of a uniaxial extrusion-molding machine(TLC35-20 type, manufactured by Tsukada Juki Mfg. Co., Ltd.) to obtainpellets.

(2) Production of Wrap Film

The pellets obtained in (1) described above were dry-blended withIDEMITSU PP (polypropylene) F-704NP (melt flow rate: 7 g/10 minutes) andF-734NP (melt flow rate: 6 g/10 minutes) manufactured by IdemitsuPetrochemical Co., Ltd. in a proportion shown in Table 1. Next, a wrapfilm having a thickness of 20 μm was obtained on film-making conditionsdescribed below by means of a VS40 extruding machine and a T die castmolding machine manufactured by Tanabe Plastic Machinery Co., Ltd.

Film-Making Conditions

-   -   Die outlet resin temperature: 230° C.    -   Chilled roll temperature: 30° C.    -   Haul-off speed: 18 m/minute        (3) Evaluation of Wrap Film

All the wrap films thus obtained were conditioned at a temperature of23±2° C. and a humidity of 50±10% for 16 hours or longer to evaluate thefollowing items at the same temperature and the same humidity. Theevaluation results are shown in Table 1.

(1) Transparency (Haze)

Measured according to JIS K 7105.

(2) Tensile Yield Strength and Tensile Elastic Modulus

Measured by a tensile test according to JIS K 7127.

-   -   Crosshead speed: 50 mm/minute    -   Measuring direction: machine direction (MD direction)        (3) Wrapping Property 1

A stainless vat (inner dimension: 125×180×depth: 70 mm) was wrapped withthe wrap film cut to 160×220 mm. A case in which the film was not peeledoff after left standing at 5° C. for one week and in which the wrappingstate was maintained was judged as ⊚, and a case other than it wasjudged as X.

(4) Wrapping Property 2

The wrap film cut to 160×170 mm was put on the mouth of the vatdescribed above apart from the short side by 30 mm and 50 mm to stickthe edge of the film closely to the angular vat. Subsequently, the filmwas drawn in order from the central end part to try to cover theaperture part. A case in which wrapping was succeeded in both of 30 mmand 50 mm and could be completed was judged as ⊚; a case in whichwrapping was succeeded only in 30 was judged as ◯; and a case in whichwrapping was failed in both was judged as X.

(5) Sticking Resistance

The angular vat was wrapped with the film as was the case with thewrapping property 1, and subsequently the central part thereof wasslowly stuck with a finger. A case in which the film was not brokenuntil the finger reached the bottom of the angular vat was judged as ⊚,and a case other than it was judged as X.

(6) Deformation (Elasticity) Restoring Property

A dice having a side of 45 mm was put on the central part of the sameangular vat as used in the wrapping property 1, and the vat was wrappedby the same procedure as in the wrapping property 1. Subsequently, thecentral part of the film was slowly stuck with a finger, and when thefinger reached the dice put on the bottom, the finger was separated fromthe film to observe the state after 3 minutes. A case in which the filmwas restored as it was before was judged as ⊚, and a case in which abag-like mark remained was judged as X.

COMPARATIVE EXAMPLE 1

A commercial polyvinylidene chloride-made film (brand name: Saran WrapR, manufactured by Asahi Chemicals Ind. Co., Ltd.) was evaluated in thesame manner as in Example 1. The result thereof is shown in Table 1.TABLE 1 Example Comparative Composition ratio (mass %) 1 2 3 4 Example 11-Butene polymer 70 70 90 50 — Olefin F-704NP 30 — 10 50 — base F-734NP— 30 — — — polymer Evaluation Haze (%) 0.4 0.4 0.6 0.6 0.3 of wrapTensile elastic 210 210 180 320 1250 film modulus (MPa) Tensile yield10.2 9.8 8.9 12.5 * strength (MPa) Wrapping ⊚ ⊚ ⊚ ⊚ ⊚ property 1Wrapping ⊚ ⊚ ⊚ ◯ X property 2 Sticking ⊚ ⊚ ⊚ ⊚ X resistance Deformation⊚ ⊚ ⊚ ⊚ X restoring property*The yield point was not found

EXAMPLES 5 TO 7 AND COMPARATIVE EXAMPLE 2

(1) Production of Pellets

The phenol base antioxidant: Irganox 1010: 500 ppm was added to the1-butene polymer obtained in Production Example 1, and the polymer wasextrusion-molded at a resin temperature of 200° C. by means of a biaxialextrusion-molding machine (laboplast mill, manufactured by Toyo SeikiMfg. Co., Ltd.) to obtain pellets.

(2) Production of Multilayer Wrap Film

EVA (ethylene-vinyl acetate copolymer) of V425 (MFR: 9 g/10 minutes,vinyl acetate content: 10 mass %) manufactured by Mitsui Du PontPolychemical Co., Ltd. was used as a material for forming both surfacelayers. Used as a material for forming an intermediate layer was acomposition obtained by dry-blending the pellets obtained in (1)described above with IDEMITSU PP (polypropylene) F-744NP (MFR: 7 g/10minutes) manufactured by Idemitsu Petrochemical Co., Ltd. in aproportion shown in Table 2. The material for forming both surfacelayers and the material for forming an intermediate layer wereintroduced into separate uniaxial extruding machines (a surface layerextruding machine: manufactured by Tanabe Plastic Co., Ltd. and anintermediate layer extruding machine: manufactured by Rikua Co., Ltd.)to plasticize and knead the respective raw materials by heating, andthen they were co-extruded from a co-extrusion three layer T die. Thelaminated film extruded was received by means of a haul off equipment sothat a laminated film of a thickness 15 μm having a constitution shownin Table 2 was obtained to prepare a two kind-three layer film. Thefilm-making conditions are described below.

Film-Making Conditions

-   -   Surface layer extruding machine: 30 mm φ    -   Intermediate layer extruding machine: 30 mm φ    -   Molding temperature: 220° C.    -   Chilled roll temperature: 25° C.        (3) Evaluation of Multilayer Wrap Film

All the wrap films thus obtained were conditioned at a temperature of23±2° C. and a humidity of 50±10% for 16 hours or longer to evaluate theitems other than a permanent elongation percentage by the same methodsas described above and the permanent elongation percentage by a methoddescribed below at the same temperature and the same humidity. Theevaluation results are shown in Table 2. The films prepared in Examples5 to 7 have a good molding property, and the films obtained have a lowpermanent elongation percentage and are excellent in a deformationrestoring property and an adhesive property.

(1) Permanent Elongation Percentage

Measured by means of an autograph manufactured by Toyo Seiki Co., Ltd. Astrip cut out from the molded film in an MD direction (machinedirection) in a size of 200 mm×15 mm was used as a test piece. Referencelines were marked on the test piece at an interval of 100 mm; aninterval between the chucks was set to 150 mm; and the film was extendedby 50 mm from this point at a speed of 500 mm/minute and held as it wasfor 30 seconds. Then, the chucks were restored to the former position ata speed of 20 mm/minute to measure a distance (L) (mm) between thereference lines in the test piece when the load was 0. The permanentelongation percentage (Pr) (%) is defined as follows:Pr=[(L−100)/100]×100

The smaller value of this Pr shows that the restoring property todeformation is higher, and it is preferred for the wrap film. TABLE 2Example Comparative 5 6 7 Example 2 Both surface layer EVA EVA EVA EVAComposition Pellet of (1) 100 68 30 — ratio of PP 0 32 70 100intermediate layer (mass %) Thickness (μm) of respective layers 5/5/55/5/5 5/5/5 5/5/5 (surface layer/intermediate layer/ surface layer)Evaluation Tensile elastic 134 149 173 177 of wrap modulus (MPa) filmPermanent elongation 9 10 11  14 percentage (%) Wrapping property 1 ⊚ ⊚⊚ ⊚ Wrapping property 2 ⊚ ⊚ ◯ X Sticking resistance ⊚ ⊚ ⊚ X DeformationΔ Δ Δ X restoring property

COMPARATIVE EXAMPLE 3

The same pellets as used in Example 5 were used to prepare a film by amonolayer T die method, but winding on the roll was caused, and a filmhaving a thickness of 15 μm could not be prepared.

EXAMPLES 8 TO 11

(1) Production of Pellets

The phenol base antioxidant: Irganox 1010 (manufactured by CibaSpecialty Chemicals Co., Ltd.): 1000 ppm and a phosphorus baseantioxidant: P-EPQ (manufactured by Ciba Specialty Chemicals Co., Ltd.):500 ppm were added to the 1-butene polymer obtained in ProductionExample 1, and the polymer was extrusion-molded at a resin temperatureof 200° C. by means of the uniaxial extrusion-molding machine (TLC35-20type, manufactured by Tsukada Juki Mfg. Co., Ltd.) to obtain pellets.

(2) Production of Raw Film

The pellets obtained in (1) described above, IDEMITSU PP (polypropylene)F-300S (melt flow rate: 3 g/10 minutes) manufactured by IdemitsuPetrochemical Co., Ltd. and a propylene base random copolymer R-PP (meltflow rate: 2.3 g/10 minutes, ethylene content: 4.2 mass %, meltingpoint: 137° C.) produced by a method described in Example-1 of JapanesePatent Application Laid-Open No. 152531/1998 were dry-blended in aproportion (mass %) shown in Table 3. Next, a tubular raw film having athickness of 240 μm was produced at a die outlet temperature of 230° C.by means of three 40 mm φ extruding machines and a one kind-three layerdown-blowing water-cooled film-making machine equipped with a 50 mm φcircular dice.

(3) Production of Stretched Shrink Film

The raw film obtained in (2) described above was biaxially stretched atthe same time at a stretching temperature of 100 to 120° C. and astretching magnification of 6 times in a longitudinal direction and 5times in a lateral direction by means of a tubular type simultaneousbiaxial stretching film-making machine in which two sets of upper andlower nip rolls were disposed and in which a heating furnace comprisinga pre-heater and a main heater was provided between the upper and lowernip rolls to produce a stretched film. Further, the stretched film thusobtained was subjected to heat treatment at 70° C. for 10 seconds bymeans of the stretching apparatus described above to obtain a shrinkfilm having a thickness of 12 μm. The shrink film was evaluated by thefollowing methods. The evaluation results thereof are shown in Table 3.

(4) Evaluation of Shrink Film

All the shrink films thus obtained were conditioned at a temperature of23±2° C. and a humidity of 50±10% for 16 hours or longer to evaluate thefollowing items. The evaluation results thereof are shown in Table 3.

{circle over (1)} Transparency (Haze)

Measured according to JIS K 7105.

{circle over (2)} Shrink Packaging Appearance

A commercial rectangular ready-to-eat Chinese noodle (chow mein) waspackaged with the shrink film obtained above leaving a little space toseal an aperture part by hot fusing. This was put on a conveyor andpassed through an NS-350 type hot air circulating type heating furnacemanufactured by Kyowa Electric Co., Ltd. to shrink the film. A size ofthe edge-rising part after heat shrink and an amount of wrinklesgenerated at the corner part were visually evaluated.

{circle over (3)} Hot Slipping Property

Evaluated by the presence of blocking caused when the shrink-packagedarticles of the ready-to-eat Chinese noodle obtained in (2) describedabove were put together to each other at the outlet of the heatingfurnace and an easiness in passing through when transported on theconveyor as they were put together.

{circle over (4)} Heat Shrink Stress

An article was packaged with the shrink film in the same manner as in(2) described above to obtain a packaged article, except that it waspackaged leaving little space. Then, it was visually observed andevaluated as ◯ in a case where no deformation was caused and as X in theother cases than it.

In Comparative Example 4, a film was produced from IDEMITSU PP F-300Salone manufactured by Idemitsu Petrochemical Co., Ltd. as apolypropylene resin. In Comparative Example 5, a film was produced fromR-PP alone used in Examples 10 and 11. TABLE 3 Comparative ExampleExample Composition ratio (mass %) 8 9 10 11 4 5 1-Butene polymer 70 5070 50 — — Olefin F-300S 30 50 — — 100 — base R-PP — — 30 50 100 polymerEvaluation Haze (%) 0.5 0.4 0.6 0.4 0.5 2.0 of shrink Gloss (%) 148 147142 140 146 127 film Shrink packaging Good Good Good Good Bad Goodappearance Hot slipping Good Good Good Good Good Good property Heatshrink stress ◯ ◯ ◯ ◯ X X

INDUSTRIAL APPLICABILITY

The wrap film of the present invention is not likely to generate toxicsubstances such as hydrogen chloride originating in chlorine indisposing and incinerating and is soft to the global environment andsafe, and it is equal in a transparency, a sticking resistance and adeformation restoring property to a wrapping film made of a polyvinylchloride resin which is used in a large quantity at present or moreexcellent in characteristics such as a sticking resistance and adeformation restoring property than the above wrapping film.

Also, the shrink film of the present invention does not contain chlorineand therefore is not likely to generate toxic substances such ashydrogen chloride originating in chlorine in disposing and incinerating.Further, it does not use a plasticizer and therefore does not causetroubles by elution of the plasticizer in use, so that it is safe andsoft to the global environment. Also, it is excellent in a heat shrinkproperty in a packaging work, a low temperature shrink property, asolvent-breaking resistance, a heat melt-sealing property, a hotslipping property and a package appearance after packaging (no wrinklesproduced and fine sticking at edges). Further, it stays in a markedlyhigher level of a transparency and a glossiness than a conventionalpolyolefin base resin shrink film and makes it possible to provide ashrink packaged article which is excellent in a product value, and theapplication fields thereof are expected to be expanded further more.

1-14. (Cancelled).
 15. A wrap film, comprising: 1 to 99 mass % of a1-butene base polymer and 99 to 1 mass % of an olefin base polymer;wherein the 1-butene base polymer comprises: (1) a melting point, Tm-D,of 0 to 100° C., as defined by the highest melting temperature peakobserved in a melting endothermic curve measured by means of adifferential scanning calorimeter; wherein the melting endothermic curveis obtained by holding a sample at −10° C. for 5 minutes under anitrogen atmosphere and then elevating the temperature at 10° C./minute;(2) a stereospecific index {(mmmm)/(mmrr+rmmr)} of 20 or less; (3) amolecular weight distribution (Mw/Mn) of 4.0 or less, as measured by agel permeation chromatography (GPC) method; and (4) a weight averagemolecular weight (Mw) of 10,000 to 1,000,000, as measured by the GPCmethod.
 16. A wrap film, comprising: 1 to 99 mass % of a 1-butene basepolymer and 99 to 1 mass % of an olefin base polymer wherein the1-butene base polymer comprises (1′) a melting point, Tm-P, that is notobserved or is from 0 to 100° C., wherein said melting point is definedas by the highest melting temperature peak observed in a meltingendothermic curve measured by means of a differential scanningcalorimeter; wherein the melting endothermic curve is obtained bymelting a sample at 190° C. for 5 minutes under a nitrogen atmospherethen lowering the temperature down to −10° C. at 5° C./minute, thenholding the sample at −10° C. for 5 minutes and then elevating thetemperature at 10° C./minute; (2′) a stereospecific index{(mmmm)/(mmrr+rmmr)} of 20 or less; (3′) a molecular weight distribution(Mw/Mn) of 4.0 or less, as measured by a gel permeation chromatography(GPC) method; and (4′) a weight average molecular weight (Mw) of 10,000to 1,000,000, as measured by the GPC method.
 17. A wrap film,comprising: 1 to 99 mass % of a 1-butene base polymer and 99 to 1 mass %of an olefin base polymer wherein the 1-butene base polymer comprises(5) a 1-butene structural unit which accounts for 90 mole % or more in a1-butene homopolymer or a copolymer of 1-butene and ethylene and/orα-olefin having 3 to 20 carbon atoms, wherein the α-olefin excludes1-butene and (6) a II type crystal ratio of 50% or less, which isobtained by melting a sample at 190° C. for 5 minutes, rapidly coolingit with ice and water and solidifying, leaving standing at a roomtemperature for one hour and then analyzing by X ray diffraction.
 18. Ashrink film, comprising: 1 to 99 mass % of a 1-butene base polymer and99 to 1 mass % of an olefin base polymer; wherein the 1-butene basepolymer comprises (1) a melting point, Tm-D, of 0 to 100° C., as definedby the highest melting temperature peak observed in a meltingendothermic curve obtained by means of a differential scanningcalorimeter; wherein the melting endothermic curve is obtained byholding a sample at −10° C. for 5 minutes under a nitrogen atmosphereand then elevating the temperature at 10° C./minute; (2) astereospecific index {(mmmm)/(mmrr+rmmr)} of 20 or less; (3) a molecularweight distribution (Mw/Mn) of 4.0 or less, as measured by a gelpermeation chromatography (GPC) method; and (4) a weight averagemolecular weight (Mw) of 10,000 to 1,000,000, as measured by the GPCmethod.
 19. A shrink film, comprising: 1 to 99 mass % of a 1-butene basepolymer and 99 to 1 mass % of an olefin base polymer wherein the1-butene base polymer comprises (1′) a melting point, Tm-P, that is notobserved or is from 0 to 100° C., wherein said melting point is definedas by the highest melting temperature peak observed in a meltingendothermic curve measured by means of a differential scanningcalorimeter; wherein the melting endothermic curve is obtained bymelting a sample at 190° C. for 5 minutes under a nitrogen atmosphere,then lowering the temperature down to −10° C. at 5° C./minute, thenholding the sample at −10° C. for 5 minutes, and then elevating thetemperature at 10° C./minute; (2′) a stereospecific index{(mmmm)/(mmrr+rmmr)} of 20 or less; (3′) a molecular weight distribution(Mw/Mn) of 4.0 or less, as measured by a gel permeation chromatography(GPC) method; and (4′) a weight average molecular weight (Mw) of 10,000to 1,000,000, as measured by the GPC method.
 20. A shrink film,comprising: 1 to 99 mass % of a 1-butene base polymer and 99 to 1 mass %of an olefin base polymer wherein the 1-butene base polymer comprises(5) the 1-butene structural unit accounts for 90 mol % or more in a1-butene homopolymer or a copolymer of 1-butene and ethylene and/orα-olefin having 3 to 20 carbon atoms, wherein the α-olefin excludes1-butene, and (6) a II type crystal ratio of 50% or less, which isobtained by melting a sample at 190° C. for 5 minutes, rapidly coolingit with ice and water and solidifying, leaving standing at a roomtemperature for one hour and then analyzing by X ray diffraction. 21.The wrap film according to claim 15, wherein the 1-butene base polymeris polymerized using a metallocene catalyst comprising a transitionmetal compound wherein a cross-linking structure is formed via twocross-linking groups and a promoter.
 22. The wrap film according toclaim 16, wherein the 1-butene base polymer is polymerized using ametallocene catalyst comprising a transition metal compound wherein across-linking structure is formed via two cross-linking groups and apromoter.
 23. The wrap film according to claim 17, wherein the 1-butenebase polymer is polymerized using a metallocene catalyst comprising atransition metal compound wherein a cross-linking structure is formedvia two cross-linking groups and a promoter.
 24. The wrap film accordingto claim 15, wherein the olefin base polymer is a propylene basepolymer.
 25. The wrap film according to claim 16, wherein the olefinbase polymer is a propylene base polymer.
 26. The wrap film according toclaim 17, wherein the olefin base polymer is a propylene base polymer.27. A multilayer wrap film, which comprises: at least one layercomprising the wrap film according to claim
 15. 28. A multilayer wrapfilm, which comprises: at least one layer comprising the wrap filmaccording to claim
 16. 29. A multilayer wrap film, which comprises: atleast one layer comprising the wrap film according to claim
 17. 30. Amultilayer film, which comprises: at least one layer comprising the1-butene base polymer according to claim
 15. 31. A multilayer film,which comprises: at least one layer comprising the 1-butene base polymeraccording to claim
 16. 32. A multilayer film, which comprises: at leastone layer comprising the 1-butene base polymer according to claim 17.33. A wrap film comprising the multilayer film according to claim 30.34. A wrap film comprising the multilayer film according to claim 31.35. A wrap film comprising the multilayer film according to claim 32.36. The shrink film according to claim 18, wherein the 1-butene basepolymer is polymerized using a metallocene catalyst comprising atransition metal compound wherein a cross-linking structure is formedvia two cross-linking groups and a promoter.
 37. The shrink filmaccording to claim 19, wherein the 1-butene base polymer is polymerizedusing a metallocene catalyst comprising a transition metal compoundwherein a cross-linking structure is formed via two cross-linking groupsand a promoter.
 38. The shrink film according to claim 20, wherein the1-butene base polymer is polymerized using a metallocene catalystcomprising a transition metal compound wherein a cross-linking structureis formed via two cross-linking groups and a promoter.
 39. The shrinkfilm according to claim 18, wherein the olefin base polymer is apropylene base polymer.
 40. The shrink film according to claim 19,wherein the olefin base polymer is a propylene base polymer.
 41. Theshrink film according to claim 20, wherein the olefin base polymer is apropylene base polymer.
 42. A multilayer shrink film, which comprises:at least one layer comprising the shrink film according to claim
 18. 43.A multilayer shrink film, which comprises: at least one layer comprisingthe shrink film according to claim
 19. 44. A multilayer shrink film,which comprises: at least one layer comprising the shrink film accordingto claim 20.